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Old August 9, 2013, 11:51 PM   #1
Bill Akins
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Need some advice on finding a certain blowback/inertia shotgun action

I'm trying to find a SEMI-AUTO blowback or inertia type shotgun action for a specific research and development purpose. I have read a bit on Benelli inertia shotguns, where the whole shotgun has to move in relation to the compressibility of the shooter's body, while the two piece spring loaded bolt head and bolt body, due to its greater weight, stay (relatively) stationary. But I can't use that type of action since it cannot work if the gun is braced against something and can only work because of the compressibility of the shooter's body, due to the whole gun having to move rearward against the shooter while the bolt head and bolt body stay relatively stationary.

It has to be a semi-auto shotgun action that could be securely mounted into a tripod type of mount, that would prevent the shotgun from moving at all under recoil. And I can't have the barrel move either like on a Browning auto 5. I need to find a semi-auto shotgun action where only the bolt will move while the barrel and the receiver stays totally stationary.

Although I've owned and fired shotguns, I'm not a real shotgun knowledgeable person. So I'd appreciate any advice of what type and brand of semi-auto shotgun might have an action like I described and any links to articles or descriptions of a semi-auto shotgun action like that.

It needs to be some sort of locked bolt that will release when pressures are safe, and does so without the barrel moving or the whole gun moving and without any type of gas tube/piston system.

Someone told me a Win model 50 might fit the bill. I don't know anything about the Win mod 50, are they correct?



.
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"This is my Remy and this is my Colt. Remy loads easy and topstrap strong, Colt balances better and never feels wrong. A repro black powder revolver gun, they smoke and shoot lead and give me much fun. I can't figure out which one I like better, they're both fine revolvers that fit in my leather".
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Last edited by Bill Akins; August 10, 2013 at 03:17 AM.
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Old August 10, 2013, 08:17 AM   #2
PetahW
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.

Bill, IMO you've either mis-read or are mistaken about the Benelli Inertia driven system.

http://www.benelliusa.com/innovations/

An ID shotgun is what you're looking for.


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Old August 10, 2013, 09:40 AM   #3
Virginian-in-LA
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Actually, that is a pretty fair description of how the inertia action works, with a few tweaks. Any inertia action is going to require the receiver to move to the rear upon firing. If you mount the tripod at the rear with a rubber bumper thick enough and with the right resiliency, the tripod portion could be fixed. That is essentially what they did with their rubber chevron stocks to reduce recoil transmission to the shooter.
You will not find a blowback shotgun action. The weight required of the breechblock would be prohibitive.
In spite of the glowing reports of a few owners, the Winchester 50 was neither popular, particularly robust, or particularly reliable.
I think you are either down to a gas system or electric powered. Why are you not considering a gas action?

Last edited by Virginian-in-LA; August 10, 2013 at 09:48 AM.
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Old August 10, 2013, 01:19 PM   #4
barnbwt
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The inertia system only needs 1/4" of movement of the bolt body to unlock, but since the two halves recoil with the shotgun as well, that translates to a longer "shoulder travel."

I owned a Franchi I12 a while back that was a Benelli twin, and I found it would not cycle reliably with light clays loads unless I intentionally shot;
-without pulling the forearm back, so my right shoulder wasn't tightly tensioned against my left, and could rotate back more
-allowing a very slight "running start" by not pulling into my shoulder firmly
-standing unbalanced, as opposed to leaning forward into the shot like I normally do

Basically, you gotta do whatever it takes to get a certain amount of recoil travel, which I believe was in the neighborhood of 1". Partly due to that, partly due to the gun not fitting me well, and partly because the inertia system is slower than others (I could always feel the bolt movement jumping around when I was trying to re-aim), I sold that gun for a Franchi O/U who's "rigid" operating characteristics were more pleasing and predictable.

As far as designing a mounted shotgun, I'd look at the operation of light deck-cannons such as the Oerlikon and for ideas. That, or incorporated a recoil-spring and barrel guides so the inertia action can operate in a controlled manner (think the old recoiling barrel anti-aircraft guns)

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Old August 10, 2013, 04:36 PM   #5
SauerGrapes
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Question. If you mount a shotgun so it can't move at all, won't the shotgun eventually recoil it self to death? I would think part of the design counts on rear movement to keep the gun from self destructing.
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Old August 10, 2013, 04:43 PM   #6
Hawg
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A true blow back shotgun would be an unwieldy beast as the counter weight would have to be huge.
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Old August 10, 2013, 05:16 PM   #7
Bill Akins
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Quote:
PetahW wrote:
Bill, IMO you've either mis-read or are mistaken about the Benelli Inertia driven system. An ID shotgun is what you're looking for.
I have read about the Benelli inertia drive system, and am pretty aware of how it works. It will not allow the shotgun to be braced. The shotgun must be able to move against the shoulder of the shooter or it will not operate the inertia action. I can't use that. I need the shotgun to not move, the barrel to not move, and only the bolt to move.

I tried looking up an "ID shotgun" but all I got were hits of people trying to identify a shotgun. What did you mean by saying I need an "ID" shotgun ?

Quote:
Virginian-in-LA wrote:
Why are you not considering a gas action?
Because a gas system is too difficult to water cool the barrel via a water jacket. Trust me, I've already tried with a Saiga 12 and although technically possible, it just isn't practical.

Quote:
Barnbwt wrote:
As far as designing a mounted shotgun, I'd look at the operation of light deck-cannons such as the Oerlikon and for ideas. That, or incorporated a recoil-spring and barrel guides so the inertia action can operate in a controlled manner (think the old recoiling barrel anti-aircraft guns)
Barn, I'm already familiar with the Oerlikon cannon and its Advanced Primer Ignition system (A.P.I. system). But the Oerlikon cannon's API system allows the primer to detonate before the shell is completely in the chamber and before the chamber is fully closed. This reduces recoil because the forward inertia of the bolt as well as the forward inertia of the weight of the shell helps to counteract the recoil. (Later note, yes it also reduces the size and weight of the bolt needed). You can find that A.P.I. info here....
http://en.wikipedia.org/wiki/Blowbac...PI.29_blowback

For a straight blow-back operated shotgun to work safely, it would have to operate from the open-bolt position with advanced primer ignition (just like the Oerlikon cannon). Maxwell Attichison(sp?) built a successful design but was of full-auto config. Of course Batfe has ruled that open bolt firearms are 'readily convertable' to full-auto & are thus considered title 3 arms.

That isn't what I'm seeking to do and the API system cannot be found on any existing shotguns that I've seen anyway and I am not interested in building a firearm that utilizes that action. Also I don't want a recoiling barrel since I plan to water cool the barrel and do not want to have to have the same moving barrel within a water jacket as the Browning 1917 machine gun, with that attendant leakage, bushings and glands that have to be tightened down that could impede operation if tightened down too much. What I am looking for is an existing shotgun, that isn't an inertia model since it will be hard mounted, and where the barrel does not move, that I can take out of its stock and use its action as it is, for my application.

Quote:
SauerGrapes wrote:
Question. If you mount a shotgun so it can't move at all, won't the shotgun eventually recoil it self to death? I would think part of the design counts on rear movement to keep the gun from self destructing.
No, otherwise non recoiling barrel tripod mounted machine guns would "recoil themselves to death". If that were true then a Gatling gun (that doesn't have a forward and backward moving barrel) would "recoil itself to death" but it doesn't. Same is true with the Gardner gun. The recoil will be absorbed by the weight of the housing that will be used to hold the two side by side shotguns as well as translate the recoil vibration into the tripod too. Which will either vibrate the tripod or move the tripod slightly depending on the amount of recoil. Just like it does with a tripod mounted non recoiling barrel machine gun, a Gatling, or a Gardner gun and many others.

Quote:
Hawg Haggen wrote:
A true blow back shotgun would be an unwieldy beast as the counter weight would have to be huge.
It takes a 25 lb bolt to operate a 30-06 blow back design. Which has more pressure than a 12 gauge does. So the 12 gauge could get by with a less heavy bolt. And if it was tripod mounted it wouldn't be unwieldy since it isn't meant to be carried but is like a heavy machine gun emplacement. But I'm hoping to not have to build a completely new shotgun receiver that is capable of using a very heavy bolt like that and that also would have to use the A.P.I. system the same as the Oerlikon cannon. I'm hoping to utilize an existing two semi auto shotguns that will be housed side by side inside a larger fake receiver that is tripod mounted and crank fired.


.









.
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"This is my Remy and this is my Colt. Remy loads easy and topstrap strong, Colt balances better and never feels wrong. A repro black powder revolver gun, they smoke and shoot lead and give me much fun. I can't figure out which one I like better, they're both fine revolvers that fit in my leather".
"To be sure of hitting the target, shoot first and call whatever you hit the target".

Last edited by Bill Akins; August 11, 2013 at 09:38 AM.
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Old August 10, 2013, 05:50 PM   #8
Jim Watson
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A water cooled fixed mount shotgun, wow.

Quote:
Someone told me a Win model 50 might fit the bill. I don't know anything about the Win mod 50, are they correct?
The Winchester Model 50 is recoil operated but the recoiling element is a sub-chamber that moves back and forth in the breech end of the barrel proper. So there is no external movement of the barrel, no need for the whole gun to recoil, no need to work around a gas port.

See the owner's manual at:
http://stevespages.com/pdf/winchester_59.pdf
That is for the Model 59 which is mechanically the same but for the innovative fiberglass barrel.

I think it might eventually pack it in because of slow heat transfer from chamber to barrel to water jacket, but it ought to run long enough for your "proof of concept."

Are you going to build from scratch on that system or cut up a production model shotgun? If the latter, what do you plan to do about the magazine?
Modifying a sporting repeating shotgun for military use requires accommodating the tube magazine. Squeezing in a water jacket will add to the hassle.
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Old August 10, 2013, 06:45 PM   #9
barnbwt
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"For a straight blow-back operated shotgun to work safely, it would have to operate from the open-bolt position with advanced primer ignition"

Actually, I was referring more to the 100+lb bolt body of the Oerlikon than its operation

The purpose of the API setup was not to reduce recoil (it's a fixed gun) but to reduce the mass of the reciprocating bolt. If fired from closed bolt, the 20mm rounds would require a 200-something pound bolt to safely fire, which would make the gun even bigger, and slow its rate of fire terribly (bad news for AA guns). As would be the case with a closed-bolt Oerlikon, you simply need to design your machine to have a heavy enough bolt (10lb or so)

Blowback is the most reliable way to go for duration-fire (or barring that, delayed blowback) because there are fewer parts to be battered (recoil action) and its tremendous fouling tolerance (gas op). I think plastic shotshells are slippery enough that they wouldn't grab the chamber walls under pressure and tear like brass does, either (not much of an issue in low pressure cartridges, but still). Since there's no carriers or gas tubes, it's way easier to make a ribbed barrel and fit a water jacket for cooling.

As I said, a 12ga closed bolt blowback would require a 10lb mass (bolt plus hammer/striker weight). Totally untenable for a carried weapon, but on a fixed platform, that may be acceptable, as well as very simple to build. You also have the benefit of 12ga being pretty low pressure, which makes it that much less likely a case failure would be catastrophic should the breech open too soon. You could easily find a big hunk of steel, drill it for a firing pin/striker setup, weld up a beefy receiver of steel plate or tubing, a dash of trigger group and machine work, some blood sweat and tears, and you'd be all set

If you don't mind my nosey-ness, what's this for? Just for fun, or do you have a reality show or something? (I kid, this thing just seems right up Red Jacket's alley is all ). Honestly, a minitature Oerlikon or similarly bad-ass anti-aircraft gun that runs on (much cheaper) shot shells would be a pretty cool toy

TCB
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Old August 11, 2013, 02:59 AM   #10
Bill Akins
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Quote:
Jim Watson wrote:
A water cooled fixed mount shotgun, wow.
Yep. Don't forget they would be twin actions and semi auto shotguns with both barrels in the same water jacket, being crank fired at a high rate of speed. Insane? Of course!

Quote:
Bill Akins wrote:
Someone told me a Win model 50 might fit the bill. I don't know anything about the Win mod 50, are they correct?
Quote:
Jim Watson wrote:
The Winchester Model 50 is recoil operated but the recoiling element is a sub-chamber that moves back and forth in the breech end of the barrel proper. So there is no external movement of the barrel, no need for the whole gun to recoil, no need to work around a gas port.

See the owner's manual at:
http://stevespages.com/pdf/winchester_59.pdf
That is for the Model 59 which is mechanically the same but for the innovative fiberglass barrel.

I think it might eventually pack it in because of slow heat transfer from chamber to barrel to water jacket, but it ought to run long enough for your "proof of concept."
Thanks for that info on the Win model 50 Jim. I appreciate it. It might just be what I'm looking for with your description of the barrel not moving at all and the sub chamber only moving a bit at the breech end of the barrel. I'll check out the owners manual you provided and thanks for providing that. In case the manual doesn't show it, how far would you say the sub chamber goes forward of the breech? Also, does the sub chamber go totally inside the barrel so that a water jacket could be put on the barrel OVER the sub chamber? Both of those questions are important to me due to water jacket cooling concerns, since I'd like to water jacket the barrel as far back as possible to cover almost to the breech. (Later note after reading the manual, yes the sub chamber goes inside the barrel, so yes I can cover the barrel with the water jacket where the sub chamber goes, so that the entire barrel is water jacket cooled). Hoo rah, sounds like I found out which shotgun actions I need.

Now I'm disgusted cause I have a few of them I was and am watching in Gunbroker and one of the mod 50's just sold for the low price of $139.00 just yesterday, and of course TODAY I find out it's the action I need and I should have bid on it. Oh well. On to the next one.

Quote:
Jim Watson wrote:
Are you going to build from scratch on that system or cut up a production model shotgun? If the latter, what do you plan to do about the magazine?
Modifying a sporting repeating shotgun for military use requires accommodating the tube magazine. Squeezing in a water jacket will add to the hassle.
Quote:
Barnbwt wrote:
If you don't mind my nosey-ness, what's this for? Just for fun, or do you have a reality show or something? (I kid, this thing just seems right up Red Jacket's alley is all ). Honestly, a minitature Oerlikon or similarly bad-ass anti-aircraft gun that runs on (much cheaper) shot shells would be a pretty cool toy
Fellas, it will look a good deal like this twin action, twin barrel, 1879 Gardner gun photo and hopper fed like that too, only in 12 gauge instead of 45-70 and firing much faster since it is semi auto and crank fired as opposed to the totally manual crank fired Gardner which fires much slower. The Gardner was the very first known manufactured water cooled gun in history. The Gardner was made in 1, 2, and 5 barrel versions. I expect my twin 12 gauge to be devastating firepower with two semi auto shotguns being crank fired either sequentially or simultaneously (depending on how I set the crank cam on the triggers). Especially devastating if crank fired simultaneously with both barrels firing at the same time. I can get six shots per revolution and possibly eight if I build the crank fire cam correctly. Six for sure, eight possibly. (But I don't want to overcrank the guns faster than they can operate which is easily done and you have to slow down cranking a bit, learned that with my 10/22 crankfires.

Can you imagine rapidly crank firing out that kind of twin 12 gauge shotgun firepower? For each 00 buckshot, that's nine 33 caliber pellets going out. A literal wall of lead. You could mow fields with it. Lol. I get a good rate of crank fire out of my 10/22 crank fires and they are all only single barrel. Twin action/barrels will be a hoot! Heavy though, what with twin shotguns and a heavy steel fake receiver housing and ammo hopper and ammo and other sundry parts, not to mention the mount/tripod, but that's okay, I need the weight to soak up recoil.



A poster asked me if I didn't have the gun or its barrel moving rearward if wouldn't that recoil the gun to death? As you can see in the above photo, the Gardner was hard mounted and its barrels did not reciprocate. All its recoil was transferred into its housing and its mount and it didn't recoil to death.

I could use a recoiling barrel but would prefer not to. Because I see how the front glands on the water jacket of moving barrel machine guns leak a bit, plus you have to machine a groove into the barrel for a packing gland and also use a bushing in the water jacket. And if you tighten the bushing down upon the gland too much to create a better water seal, it will cause friction and impede the operation of the gun. So it is common to see a moving barrel 1917 water cooled Browning leaking when firing when the barrel is moving back and forth in the front bushing.

The Gardner gun didn't have moving barrels. Neither do my other crank fire inventions. I have quite a bit of experience in building something like this since I have built three prototypes of air cooled and water cooled fake receiver dress up kits for the Ruger 10/22 that look like Browning air cooled and truly water cooled machine guns, that are crank fired. My final third prototype is quickly convertible from air to water cooled in just a minute. So it can be both versions. Here's a few pics. I finally have the funds to finance buying the two shotguns and fabricating the fake receiver and water jacket hopefully using Win mod 50's that you described if they work out to what I need, since I have been unable to find anything else that is available that fits that description. I've been planning on doing this for quite some time and I want to get it done, but I need to make sure I get the correct two shotguns to do it with. These are my three prototypes and is what I want to build only on a larger scale and in double barrel using two semi auto shotguns that will be hopper fed and triggers connected for crank firing like a Gardner or Gatling.

You can see a slideshow of my first two prototypes here. The (1st prototype) air cooled one is ONLY able to be air cooled. The (2nd prototype) water cooled one is ONLY able to be water cooled.
http://www.youtube.com/watch?v=2F7f1...4C25D49F70EA08

Crank fire attachment not installed on trigger in three below pics, (but it is installed now). My third and final prototype is able to be convertible so it can either be air cooled like this.....




Or quickly converted in just a minute to truly water cooled like this....






I'm inverting the shotguns so I can omit their tube feeds and gravity hopper feed them instead. With the heat they will generate with a high capacity hopper feed, I won't be making an air cooled version since it would overheat much too quickly. They will be water cooled only.

The only thing holding me back is making sure I know the correct model shotguns to buy for this application. No sense wasting money if they aren't correct for the application. Now you fellas know why I need a semi automatic shotgun that the barrel doesn't move on. I want to easily fit a water jacket onto the barrels just like I did the STATIONARY barrels on two my three crank fire Ruger 10/22 prototypes. Which said 10/22's by the way, aren't modified in any way. I worked my fake receiver, barrel shroud, and water jacket around the existing design without any modifications to the 10/22 whatsoever.

They can be removed from my fake receiver dress up stocks and placed back in a factory Ruger stock if desired. No mods at all. Just fabrication all around the existing action and barrel. Sorry, I forgot. One mod. The end of the barrel is threaded 1/2x28tpi to screw on the flash hider which also secures the front O ring that seals the front of the water jacket. The rear of the water jacket has an angled cut that forces another O ring into it and at the same time forces that O ring even tighter to the barrel via the angled cut in the rear of the water jacket, and that O ring is also pressed against a flat plate on the front of the fake receiver which creates a very effective water seal at the rear of the water jacket. That's the same way I want the water jacket to seal on the shotguns. So I need them to have stationary barrels.

It's time now for me to do the same thing only in twin action double barrel 12 gauge scale. But the guns have to be the right ones for the job and that's why I was asking for advice about what semi auto shotguns do not use a moving barrel and that can operate while being totally motionless and braced inside a fake receiver housing. So far from Jim Watson's description, the Win mod 50 seems like the best choice, in fact the ONLY choice as far as I can tell. Too bad I can't use a more currently produced shotgun for this. But at least the Win mod 50 is still available to have used.

Now you can better understand what it is I'm wanting to build. It will of course not look as much like my Ruger 10/22 crank fires, but will look a great deal like the double barrel, water cooled, Gardner gun pictured earlier in this post. It will either have a funnel like hopper feed that feeds both guns with the sights being in the middle cut out of the feed, or it will have twin vertical feeds over each gun's receiver. I haven't decided yet.

And before anyone asks, yes it is legal. It's a crank fire just like a Gardner or Gatling, just like my Ruger 10/22's. Actually, legally the entire housing is just a "stock" under the law. And it will be at least 26 inches in length, probably way more, with at least an 18 inch barrel, again probably way more, and is intended exclusively for heavy mount or heavy tripod use...naturally. Skeet shooting anyone?

I'm going to be sixty in October, and I just found out a few days ago the results of the MRI on my spine from the surgeon, that I have a tumor/cist in my spine that has pressed down by HALF my sciatic nerve causing severe pain and I am only vertical because of the steroids the doc has me on to reduce the swelling. I go in for surgery to remove it on tuesday and will be out of commission for a month to heal up. So I'm feeling my age and recognize that if I don't get some of my designs done NOW, while I still have a few good years left, I might never get them done. So I'm getting very serious about doing this while I still can, and can have some fun with it, before I get too old to lug something like this around to the range. Know what I mean some of you guys my age?


.
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Last edited by Bill Akins; August 11, 2013 at 11:18 AM.
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Old August 11, 2013, 09:51 AM   #11
barnbwt
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You've got the room, just do a direct blowback with a heavy bolt. Easier in every way . Have a crank operated striker (it'd be a DAO crank, if that makes sense) and use the bolt for feeding and extraction only. Super simple.

TCB
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Old August 11, 2013, 09:54 AM   #12
Husqvarna
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dunno if this helps but that gun show from Alaska found some rem1100 that were mounted to a airplane, like four in a row under each wing. Would that count as stationary?

hope the surgery goes well
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Old August 11, 2013, 10:43 AM   #13
Bill Akins
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Quote:
Barnbwt wrote:
You've got the room, just do a direct blowback with a heavy bolt. Easier in every way . Have a crank operated striker (it'd be a DAO crank, if that makes sense) and use the bolt for feeding and extraction only. Super simple.
Yes I could do that Barn. But that would be a lot of hassle to get the bolt just the right amount of weight, the springs correct, build the heavy firing pin, trigger etc, etc, etc. Not to mention still having to build the hopper feed, water jackets and housing for it all. Could I do it? Yes, but that's an awful lot of work when instead if I can use two Win mod 50's and invert them, that saves me almost all the actual firearm work and I can just concentrate on building the hopper feed, housing, water jacket and the crank and its extension rod to the other gun's trigger. Much much easier that way and would get done faster.

Below, I posted a link to a thread on blowback shotguns discussion y'all should read all four pages of since it is very informative, where a fellow in it on page two, named Ossi from Iceland, had tried to build a blowback 12 gauge out of raw channel steel and made his own heavy bolt, receiver and barrel and experimented with it. He showed good pics of his work. He gave up on it after it blew cases, but he admits that he didn't make his bolt heavy enough and that if he had, that it would have worked. He didn't mention it, but perhaps his springs were not strong enough either.

In the first sentence of his post on it, he said: "Actually I can tell you that it does NOT work". (Which is incorrect) and he later contradicted himself when he said: "I gave up on this idea because of weight. It can be made to work with an even heavier bolt but that would not be a gun you would like to carry upland hunting."

So it would work in spite of his first sentence in his first post. And he admits he just didn't make the bolt heavy enough. And that he gave up on it because of the weight, and said it wouldn't be a gun to carry hunting. Well DUH!!! Of course you aren't going to carry a beast like that around to go hunting on foot! Sheez. I guess it never occurred to him to tripod mount it. Oh well, can't expect perfection, at least he had a good idea on trying to make the blowback action work. And it would have too, if only for a heavier bolt and perhaps different springs.

So although Ossi said at first that it would not work in blowback, and later contradicted himself saying it WOULD work if he had made his bolt heavy enough, I have to at least give him credit for experimenting and trying. That's more than most people would do, and it was very informative in case I ever DID want to build one like you suggested Barn. What Ossi built, almost mirrors what you suggested I build Barn. Only it appears to me that his was open bolt, and that would not be allowed here because of the BATFE. So his design would have to be modified to a locked bolt. So another thing to have to build and overcome.

Too many things to build from scratch like that. I'm better at working around an already existing design. Yes I could do it from scratch, but I don't want to take the time and effort to do that if I can use two already existing Win mod 50 shotguns that will work for the same application. Why make it hard on myself?

Then I can spend most of my time working on the housing to house them in, and the hopper feed and crank fire attachments. That way it would get done a lot faster. There are other designs I have that I want to work on also and I don't want to spend an inordinate amount of time experimenting on just getting TWO homemade blowback receivers working when that time could be better spent. But if for any reason the Win mod 50's don't work for my application, then I will revisit what you suggested and what I saw that OSSI built. Here's that link, enjoy....
http://www.homegunsmith.com/cgi-bin/...4;t=21392;st=0



.
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"This is my Remy and this is my Colt. Remy loads easy and topstrap strong, Colt balances better and never feels wrong. A repro black powder revolver gun, they smoke and shoot lead and give me much fun. I can't figure out which one I like better, they're both fine revolvers that fit in my leather".
"To be sure of hitting the target, shoot first and call whatever you hit the target".

Last edited by Bill Akins; August 11, 2013 at 11:33 AM.
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Old August 11, 2013, 11:06 AM   #14
Bill Akins
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Quote:
Husqvarna wrote:
Dunno if this helps but that gun show from Alaska found some rem1100 that were mounted to a airplane, like four in a row under each wing. Would that count as stationary?
It depends on what you are calling "stationary". The guns may have been hard mounted to the wings and thus were "stationary" in that regard (not spring loaded on the wings to dissipate recoil perhaps). But what I need are two shotgun's actions that can remain stationary in that they are securely held in a heavy duty steel fake receiver and do not move in relation to that fake receiver, and I need them to not be gas operated, and for their barrels to remain stationary and not to move under recoil. From what Jim Watson has described, and now that I've read the manual he provided the link to, I think the Win mod 50's will be just the thing, and it appears that the sub chamber goes inside the barrel so I can put a water jacket all the way back against the very front of the receiver so the chamber and barrel will have as much maximum cooling as I can possibly make it. As Jim mentioned, although the sub chamber fits inside of and touches the barrel (inside) the heat transfer of the sub chamber to the barrel is delayed since it isn't actually a part of the barrel, and thus the sub chamber will no doubt get hotter than the barrel will. But I think that enough heat transfer will occur from the sub chamber to the barrel and then be carried off by the water cooling jacket so that the sub chamber won't fail. I could be wrong about that, but I think it will be adequate for cooling even at a high rate of crank firing. But time and shooting it would tell for sure.

Quote:
Husqvarna wrote:
Hope the surgery goes well
Thanks very much Husqvarna, very thoughtful of you to say so.



.
__________________
"This is my Remy and this is my Colt. Remy loads easy and topstrap strong, Colt balances better and never feels wrong. A repro black powder revolver gun, they smoke and shoot lead and give me much fun. I can't figure out which one I like better, they're both fine revolvers that fit in my leather".
"To be sure of hitting the target, shoot first and call whatever you hit the target".

Last edited by Bill Akins; August 11, 2013 at 11:11 AM.
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Old August 11, 2013, 11:32 AM   #15
BillM
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OK--dumb question time. You say you are going to invert the actions
and run 2 side by side. Got that--should work. But how is the right one
going to eject? Isn't the ejection port on the inverted right gun up against
the receiver side of the left gun?

Question 2: Why not have the barrel move within the water jacket? Lots
of the old watercooled machine guns did. They had a bearing at the front,
the barrel slid back and forth within the bearing at each shot.

Winchester model 50. There was an article on it in the most recent
Guns and Ammo or maybe American Rifleman. Worth the read, it gets into
detail about the operation of the gun.
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Old August 11, 2013, 11:49 AM   #16
Bill Akins
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Quote:
BillM wrote:

OK--dumb question time. You say you are going to invert the actions
and run 2 side by side. Got that--should work. But how is the right one
going to eject? Isn't the ejection port on the inverted right gun up against
the receiver side of the left gun?
Not a dumb question at all BillM. But a simple solution. The guns won't be jammed up right against each other. There will be enough space between the two guns for the right gun's spent shell to eject. A shell deflector on the inverted right gun to deflect the spent shell downward out the bottom of the open bottom fake receiver, while the left gun ejects out of a cut out in the left side of the fake receiver housing.

Quote:
BillM wrote:
Question 2: Why not have the barrel move within the water jacket? Lots
of the old watercooled machine guns did. They had a bearing at the front,
the barrel slid back and forth within the bearing at each shot.
Yes and the Browning 1917's leak at the front. On water cooled Maxims and Vickers their barrels have to be thick enough to allow a groove to be machined into them for the packing gland to wrap into (usually greased twine) to bear upon the bushing for water sealing. A shotgun barrel isn't going to be thick enough to machine a packing gland groove into, plus I'd have to build close fitting bushings. I don't want it to leak and too much hassle building all that when it is much easier to just use a stationary barrel of the Win mod 50. Just a sweated on plate over the barrel at the front of the receiver on the rear and a simple sweated on threaded bushing sweated onto the front of the barrel, some O rings, washers and nuts, and it's done. No leakage and much much easier to build. Same similar setup as the water jacket on my third prototype crank fire 10/22.

Quote:
BillM wrote:
Winchester model 50. There was an article on it in the most recent
Guns and Ammo or maybe American Rifleman. Worth the read, it gets into
detail about the operation of the gun.
Yes that appears to be the action I need. Someone some time ago told me that one might fit my bill, and now that Jim Watson provided me the link to the manual, and I see how the sub chamber fits into the barrel so that the sub chamber recoils WITHIN the barrel while the barrel stays stationary, and that I can cover both the barrel and sub chamber with a water jacket, that is what I need. No gas operation and no moving barrel.

If you could find out what month issue and magazine that mod 50 article was in and let me know, I'd sure appreciate it. I need to find out EVERYTHING I can about the Win mod 50. I need to know how to take it apart and put it back together again as second nature, and how all the parts interact between each other. I'm going to get VERY familiar with that shotgun. A shame it is no longer manufactured.


.
__________________
"This is my Remy and this is my Colt. Remy loads easy and topstrap strong, Colt balances better and never feels wrong. A repro black powder revolver gun, they smoke and shoot lead and give me much fun. I can't figure out which one I like better, they're both fine revolvers that fit in my leather".
"To be sure of hitting the target, shoot first and call whatever you hit the target".

Last edited by Bill Akins; August 11, 2013 at 11:59 AM.
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Old August 11, 2013, 01:39 PM   #17
Jim Watson
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Posts: 11,025
I suggest you start with one Model 50 so as to avoid the expense of two in case it won't work.

There was a FFL/gunsmith in this area who said that while he was in the army, he was tasked to set up a riot jeep. He allegedly converted an A5 to full auto and fed it through a large diameter hose from a hopper of shells in the jeep. Shells were propelled up the hose by compressed air. Right.
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Old August 12, 2013, 01:45 AM   #18
Bill Akins
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Quote:
Jim Watson wrote:
I suggest you start with one Model 50 so as to avoid the expense of two in case it won't work.
I will be acquiring the model 50's one at a time. As soon as I receive the first one, I will take it apart and clean it and familiarize myself totally with its action, while also reading some online articles about what to look out for when disassembling and reassembling. Then I will test fire it. If everything works like it's supposed to, then there should be no reason to think it wouldn't likewise work if I take the stock off and mount it in a heavy steel housing. Then I'll do the same cleaning and testing procedure with the second one and then build the housing to fit them both into.

I'll probably test them in the housing with crank firing them using their tube feeds first. Then I'll remove their tube feeds and create the hopper feed for them. Shouldn't be any problems as long as the shotguns work and have no issues when I receive them. Nothing would be changing about how their action operates. The trickiest thing I expect will be building the hopper feed and making that work to feed instead of the tube feed. But as far as the guns themselves operating in the housing, shouldn't be any different than if they weren't in the housing.


.
__________________
"This is my Remy and this is my Colt. Remy loads easy and topstrap strong, Colt balances better and never feels wrong. A repro black powder revolver gun, they smoke and shoot lead and give me much fun. I can't figure out which one I like better, they're both fine revolvers that fit in my leather".
"To be sure of hitting the target, shoot first and call whatever you hit the target".
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Old August 12, 2013, 09:11 AM   #19
Jim Watson
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Agree, the hopper feed will be the trick.
Do you propose to just take out the lifter and let shells stack up on the bottom of the inverted bolt?
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Old August 12, 2013, 05:03 PM   #20
Bill Akins
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Quote:
Jim Watson wrote:
Agree, the hopper feed will be the trick.
Do you propose to just take out the lifter and let shells stack up on the bottom of the inverted bolt?
That was my first thought, and that may work fine. However, it may not and there may be complications. By allowing the shells to lay on top of the bolt, depending on what projections are on the bottom of the bolt (that I don't know yet) that may not be possible.

I may have to create some sort of mechanism in the hopper to hold the shell up just off the bolt's bottom so that as the bolt flies back, it trips a mechanism that allows the shell to fall only after the bolt is rearward.

Also I may have to consider shell "jump" due to recoil and the bolt flying back, which may tend to cause the shells to jump up a bit and thus not feed or jam. I may have to forget using a funnel shaped hopper feed and go to a twin vertical feed (exactly like Gardner did on his double barrel gun) that has a weight placed on the topmost shell in the hopper to prevent that jumping. Because even if it works fine with the weight of a full hopper load of shells on the bottom most shell, what is going to happen when that weight decreases and it gets to the last few shells in the hopper? Will they jump then?

Gardner was able to get away without having a weight on top of his cartridges in the hopper, because his gun was totally manually operated via a crank, for all operations of feeding, firing, and extracting. But I am only going to be using a crank to trip the triggers of two semi auto shotguns, and thus they are going to be running a LOT faster than the Gardner ever did. With Gardner's gun running much slower, his cartridges had more time to gravity drop to be fed than my shells will. That could create a problem where my guns are firing faster than just gravity can drop the shells in time to be fed.

In that happens, I'd have to create a weight that would fit on the outside of the hopper and have a 90 degree projection that laid over the topmost shell, so the weight would take the place of the tension of a magazine spring, so my shells would be forced to feed faster than just using gravity. These are things I'm going to have to experiment with and just see. But it's all these kinds of things one has to think about. A HOST of things one has to consider.

I also need to consider the rim of the shells so that the rim of a shell above another shell doesn't go over and in front of that lower shell's rim, thus stopping that lower shell from moving forward to be chambered. Gardner had that problem as well and had his rims stacked directly in line with each other so no rim ever got in front of another rim.

I can see it in how his rimmed 45-70 cartridges stack rim edge to rim edge in his hopper feed. Instead of making a curved hopper feed, he just let air space exist between the bodies of his cartridges, and that allowed the cartridges to "droop" more and more the higher up in the hopper stack they were. That happens because for each succeeding rim, that increases the space the next cartridge body has between it and the previous bottom cartridge. Obviously Gardner made the rim grooves in his hopper very deep to allow for this droop. So that the hopper grooves held the rim, but as more and more cartridges were stacked thus more and more space was created between the bodies of the cartridges and thus the need for a very wide distance of thickness in the hopper's rim grooves to allow the higher cartridges to droop more and more. The grooves had to be sufficiently deep so no binding of the cantilevered rims in the grooves would occur.

I could do the same thing, but to avoid that altogether, I might even think about making a curved hopper feed. Notice the "drooping" of the cartridges in the Gardner gun's twin vertical hopper feeds to see what I am talking about in this below pic....



It's hard to tell in the above pic that there are two vertical hopper feeds, but you can still see the droop of the cartridges. Below, here's a better pic of the twin hopper Gardner feed, only without any cartridges in them. In this pic you can also see that the depth of the rim grooves is very deep to allow for "drooping" so the cartridge rims wouldn't bind in the hopper grooves. It also appears to me that the depth of the hopper grooves decreases as the hopper gets closer to the bottom, because the cartridges were less drooping the closer they got to the bottom, so less groove depth was needed and also it aided to align the cartridges better for feeding into the chamber as they got closer and closer to the bottom of the hopper feed.




I could get lucky and just let the shells stack on top of the bottom of the bolt and that MIGHT work. I also could get lucky and not have any problems with shell "jump". But my experience with firearms and mechanical things in general tells me that things are rarely simple and problems come up that one didn't consider and usually involve complications to overcome. So I try to think ahead design wise toward what possible problems could be before they happen, and then design accordingly. But even with doing that, things still come up that I didn't consider.

So it depends on what the bottom of the bolt looks like, and if I encounter shell "jump", and I'll just have to experiment and probably redo things several times until I get a workable hopper feed. It will no doubt involve a lot of frustration and a lot of patience. That's the main reason I didn't want to build a whole firearm from scratch. Just overcoming the challenges I listed above and modifying and adapting an already existing firearm to do this is going to be enough of a challenge. But no twin actions, twin barreled, water cooled, tripod mounted, semi auto, hopper fed, crank fire activated, shotguns exist to buy. And if they did, they would be exorbitantly expensive. So if I want one, I have to either build both firearms and EVERYTHING from scratch, or else do what I am planning to do with two EXISTING shotguns.


.
__________________
"This is my Remy and this is my Colt. Remy loads easy and topstrap strong, Colt balances better and never feels wrong. A repro black powder revolver gun, they smoke and shoot lead and give me much fun. I can't figure out which one I like better, they're both fine revolvers that fit in my leather".
"To be sure of hitting the target, shoot first and call whatever you hit the target".

Last edited by Bill Akins; August 12, 2013 at 06:17 PM.
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Old August 12, 2013, 11:14 PM   #21
Bill Akins
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Join Date: August 28, 2007
Location: Hudson, Florida
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Don't think I'm ignoring anyone's reply posts. I'm going in for spinal surgery today (Tues). I'll have my wife set up my laptop in my bed while I recuperate, so maybe in a few days I'll be able to be here for discussions.



.
__________________
"This is my Remy and this is my Colt. Remy loads easy and topstrap strong, Colt balances better and never feels wrong. A repro black powder revolver gun, they smoke and shoot lead and give me much fun. I can't figure out which one I like better, they're both fine revolvers that fit in my leather".
"To be sure of hitting the target, shoot first and call whatever you hit the target".
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Old August 20, 2013, 06:32 AM   #22
Bill Akins
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Join Date: August 28, 2007
Location: Hudson, Florida
Posts: 1,030
Back home from spine surgery and recuperating nicely now, in case anyone would like to discuss more on design ideas for a double barreled, tripod mounted, hopper fed, crank fired, water cooled, shotgun. Hopefully I'll be able to do more than just discuss design ideas, as soon as I heal up well enough to get back out in my shop.



.
__________________
"This is my Remy and this is my Colt. Remy loads easy and topstrap strong, Colt balances better and never feels wrong. A repro black powder revolver gun, they smoke and shoot lead and give me much fun. I can't figure out which one I like better, they're both fine revolvers that fit in my leather".
"To be sure of hitting the target, shoot first and call whatever you hit the target".
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