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madhat
August 15, 2012, 04:42 PM
i've been doing quite a bit of research and i've come across a very interesting line of rifles with a special feature called BOSS, it's a adjustable choke for the tip of your barrel

has anyone ever dealt with one in person and has experience with it?

i was thinking of buying the Browning composite stainless steel stalker -BOSS for 1,200$ is there better for that price?

if so what and why :) thank you for the feed back

dahermit
August 15, 2012, 04:51 PM
it's a adjustable choke for the tip of your barrelAu contrair...it is not a "choke", it is a barrel weight adjustment system that supposedly lets a shooter "adjust" the vibrations in the barrel when it is fired to get better accuracy.

Beentown71
August 15, 2012, 04:51 PM
Not really a "choke". I have one in 22-250 and it is a shooter. Loud as hell though....unbearable loud.



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Beentown71
August 15, 2012, 04:55 PM
http://i524.photobucket.com/albums/cc329/beentown71/1121091656-1.jpg

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madhat
August 15, 2012, 05:01 PM
is that a browning? looks great by the way

WillyKern69
August 15, 2012, 06:35 PM
I have a Browning Safari in 30.06 with a BOSS system. when it is "dialed in" I have 1' groups out at 200 yards. However, "dialing it in" is a task. The numbers must be zeroed on the sysytem then the number dial lock tited. If it is allowed to shift you have just wasted a lot of time and money. Then you have to pick the round. I use a remington accubond 30.06, 165 grain, with a Nosler tip and boat tail bullet. Buy a few boxes of your ammo. I would shoot three round groups. Ajust the setting either way(right or left), but get them to come together. Keep working untill you have it dialed in. The Boss is super loud and does help with the recoil. Once it is "dialed in" you will know the sweet spot. I only use one type of ammo, but you can keep a card of the setting if you change ammo. There was a time when some ammo had a starting number to set the Boss so it would take less time to dial in. If used properly it adds accuray that only the bench guys know.
WK

madhat
August 15, 2012, 06:56 PM
what would you say is best for desert plain hunting, i live in nevada and plan on hunting all northern american game

WillyKern69
August 15, 2012, 08:38 PM
If you are asking me, all I can say there are prolly other people here that can answer that question better. I do a lot of deer hunting so I wanted a medium caliber with a flat shooting bullet that won't break my arm or bank. I think 30.06 is a good all use bullet. You can use 185 grain or go light with a 155 grain. I quess it depends on what you shoot at. I feel I could take any animal in North America with a 30.06. Just my opinion before the hate posts appear.
WK

madhat
August 15, 2012, 10:16 PM
Thanks for the reply I guess I'm going for the browning composite stalker 30.06 stainless steel 849

Scorch
August 16, 2012, 12:12 AM
madhat-
I used to live in Reno and have hunted all across the west. A 30-06 will surely do everything just fine. May not shoot quite as flat as a 270 or 25-06, or have as much on-paper oomph as a 300 Magnum, but it will work just fine. And all that talk about needing a super-flat shooting rifle is based on a small percentage of the shots you will ever be given. Just to give you a perspective, I have hunted with a 7X57 on and off for years. My farthest shot while I lived in NV was about 400 yds, easily doable with a 30-06. So yes, some guys with their 257 Weatherbys or 7mm RUMs may shoot half a mile, but generally you can get closer without too much effort, and your shot will be more likely to hit what you are aiming for.

BTW, you can get the BOSS system without the ports on the BOSS, it will be a lot more pleasant to shoot.

Mike Irwin
August 16, 2012, 06:39 AM
I was working for American Rifleman when the BOSS system came out.

I thought it was a bunch of hooey when I first heard about it.

Then I got to shoot one, and was thoroughly convinced. The weight changes the harmonics of the barrel, and it's absolutely amazing how quickly you can dial in just about any load.

Keg
August 16, 2012, 08:56 AM
I have the BOSS system on a Model 70 Winchester FW..300 win mag....I have no problem with the noise..heck it's loud anyway....lol....But it is amazing how much recoil is reduced..and it is super accurate....I have the same gun..same caliber..no BOSS..also....So I have a good comparison....

madhat
August 16, 2012, 09:31 AM
how easy is it to dial in the boss? what if your boss is set for say 150 yards and a animal is 250 yards, how easy it it to dial in the boss to hit the target? what if you shoot? how far would it be off if the boss is dialed in wrong, sadly never using one i have to ask all these questions :)

Scorch
August 16, 2012, 10:57 AM
You don't dial it in for a specific range, you tune the harmonics of the barrel so it shoots the best possible group. Then, if you are sighted at say 200 yds and an animal pops up at 300, you know your load is shooting the tightest group possible and you can hit the animal at farther ranges because the groups are consistent and shot dispersion will be minimal.

math teacher
August 16, 2012, 01:22 PM
Scorch, I agree with your view on long range game shots. Madhat's choice of a 30-06 will serve him well up to moose. If he later chooses to take on brown bear, I suggest moving up to somthing like the 338. For now buy the 06.

Sandbar
August 16, 2012, 11:04 PM
The boss is as described above but it comes in two forms: (1) with muzzle brake which is pictured above -- and is the loud version), and (2) no muzzle brake. Either alters the vibrations, but the muzzle brake version affects the barrel rise and the felt recoil (a 30-06 round feels like a 243, for example)

Picher
August 17, 2012, 06:29 AM
I wouldn't buy the rifle with the BOSS, but I would with the plain barrel. I handload and the BOSS won't do anything I can't accomplish by careful handloading. Noise when hunting without ear protection is the primary concern, but tuning the rifle for each different bullet weight/manufacturer is a pain.

I've recently shot Browning bolt rifles without the BOSS and they shot very well indeed, even with factory ammo!

jgcoastie
August 17, 2012, 07:06 AM
I had a Browning BAR MkII Safari in .30/06 with BOSS (Ballistic Optimized Shooting System).

Once I had it dialed in to the different ammo types I used, it worked great. It is a good way to dial in your groups.

Here's a link to Browning's recommended starting point for tuning your BOSS to your ammo type.

http://www.browning.com/customerservice/qna/detail.asp?ID=109

cat9x
August 17, 2012, 07:52 AM
My primary hunting rifle for the past 6 years has been a MKII BAR in .270win w/ BOSS. Let me first say this Browning is very accurate, up there with bolt guns. 5/8"-7/8" groups at 100 yards consistently year after year.

As others have indicated, yes the ported BOSS does add muzzle blast however the advantage in recoil reduction and faster followup shots outweighs that (at least for me). I have tried a few setting on the Boss system. The first of which was the factory recommended "sweet spot" for the brand and bullet weight of my chosen cartridge. Groups were mediocre with this setting. Interestingly enough the best groups I get, with my chosen cartridge, is setting the BOSS to "0" and the micro-adjustment to "2".

Anyways, that's my personal experience with the Boss. I love the reduced recoil and if I'm honest, I think it looks pretty cool too :D

saands
August 18, 2012, 03:59 AM
I built a Mauser in 243 several years ago and I did a fair bit of research (patent office is a good place to get Browning's engineers version of the story) on the BOSS and built myself a non-brake version. Contrary to what some might tell you, it CAN do things that you can't do with just careful reloading. For example, it allows you to make your loads run as close to maximum for your rifle as is safe and then lets you tune the rifle so THOSE loads are also the best shooters ... sometimes you can get lucky and have the max loads be what your rifle likes without a BOSS, but it happens every time with a BOSS. Prairie dog sized targets at 300+ yds are non-issue for that 243.

All that being said, I wouldn't get the one with the brake for the hearing issues that accompany it ... but the non-ported versions are winners.

Saands

natman
August 18, 2012, 05:32 AM
It's not a choke, it's called a "tuner". It allows you to match the way the barrel vibrates to a given load, rather than changing to load to match the way barrel vibrates.

It works well, although there is a fair amount of setup for a given load. So it makes sense IF you plan to use one specific load in the rifle. You'll shoot up a fair amount of ammo if you change around a lot.

Most BOSS rifles come with a muzzle brake weight, which has the advantages (reduced recoil) and disadvantages (hellacious noise) of any muzzle break. Browning does sell the a non-muzzle brake weight as the CR version.

Joe Chicago
October 8, 2012, 12:14 PM
Could one not achieve the same goal - reduce the harmonic vibration and improve accuracy - by using a barrel de-resonator? You could avoid the increased report caused by the Boss system.

http://reviews.cabelas.com/8815/227667/sims-limbsaver-barrel-de-resonator-reviews/reviews.htm?page=2

natman
October 8, 2012, 03:49 PM
The goal isn't really to reduce the vibration, but rather match the vibration to the barrel/load. As noted above, you can get a non-muzzle break version of the BOSS weight that won't increase noise.

Magnum Wheel Man
October 8, 2012, 04:14 PM
these guys have pretty much summed it up... I will add, it does reduce the felt recoil alot... perhaps both because of the additional weight at the muzzle, & the ports... I have both a 338 Win Mag & a 375 H&H Stainless Stalkers, both with BOSS... both are more accurate than I am, & neither one is much different than shooting a .308 / 30-06

BTW... I don't personally think it's louder than the same rifle without the BOSS & with a 2" shorter barrel... the ports are not angled towards the shooter, so the "effect is no different than a 2" shorter barrel

Freakdaddy
October 8, 2012, 07:49 PM
Some of the other posters summed it up nicely on how the BOSS works so really nothing I can add to that. I will say I have the BAR Safari in .270 and just using the recommended settings in the owners manual, can constantly put 5 rounds of Winchester 130gr Ballistic Silvertip in under 1" at 100 yards. I wouldn't be surprised if I couldn't improve by messing with dialing it in but I'm very pleased with the performance so I don't bother. It is loud if you're shooting off a bench that has a roof over it but out in the woods or field, you don't even notice it. It's amazing how much it does reduce recoil and if you are sensitive to the blast, they also come with an attachment that's not ported that functions the same but the recoil and muzzle report is the same as any non-BOSS rifle. If given the choice, I will opt for the BOSS everytime as I think it's that beneficial.

As far as caliber goes for your intended purpose, the .30/06 is a fine choice but I would take a long hard look at the 7mm Remington Magnum. A little flatter shooting and with very few exceptions, harder hitting then the '06 and ammo easily available although not as many options in various weights as the '06. A little much for Pronghorns but not overkill and with some of the distances you may actually find yourself shooting at, the extra punch would be appreciated especially if it's on a large bodied Muley or an Elk.

warbirdlover
October 8, 2012, 11:34 PM
Could one not achieve the same goal - reduce the harmonic vibration and improve accuracy - by using a barrel de-resonator? You could avoid the increased report caused by the Boss system.

JoeChicago

I played with the LimbSaver de-resonator on my Ruger which was already a sub-MOA rifle. I moved it all over and didn't see any improvement, however I know it works on rifles that don't shoot good groups from talking to others at the range. Looks like heck though. I don't think it's nearly as effective as the BOSS system but a whole lot cheaper.

Schroll down on this link and look at the "AIM" system installed by Gander Mountain gunsmiths....
http://www.gandermountain.com/gunsmith/accurizing.shtml

When I'd run into a wall trying to get better groups out of a rifle with a free floated barrel I'd try putting pressure on the barrel. On some rifles this works!

.

Bart B.
October 9, 2012, 04:00 PM
Browning claims their BOSS adjusts the barrel whip frequency so the bullet leaves when the barrel's stationary. Impossible.

The barrel's never stationary after the primer detonates and burns the powder creating a pressure curve. It wiggles and whips all the time the bullet goes down the barrel and continues for a bit after the bullet's left.

If someone thinks the best place for the bullet to exit is when the muzzle axis is at its highest angle, they need to rethink that. Browning's never proved this happens with their BOSS. Neither has anyone else as far as I know.

'Twas proved over a hundred years ago that the best place for bullets to exit is just before the muzzle angle reaches its highest value as it swings up. Handloading ammo can do this; use the powder charge that gives the smallest many-shot groups at the desired range. With factory ammo, the BOSS may be adjusted to accomplish the same thing, but there's no guarantee.

barnbwt
October 9, 2012, 08:55 PM
I've been intrigued by the BOSS system since it appears it actually works to improve accuracy, moreso since I own a BAR-based FNAR. Does the device just screw onto a threaded barrel, or is there more to it than that? It's basically a position-adjustable muzzle-break/weight, right? I'm suprised other makers aren't ripping off the concept (patents, I guess...)

TCB

Keg
October 10, 2012, 11:41 AM
If the gun has a BOSS on it....That is a plus for me....

natman
October 13, 2012, 03:28 AM
Browning claims their BOSS adjusts the barrel whip frequency so the bullet leaves when the barrel's stationary. Impossible.

The barrel's never stationary after the primer detonates and burns the powder creating a pressure curve. It wiggles and whips all the time the bullet goes down the barrel and continues for a bit after the bullet's left.

You're right, the barrel does "wiggle and whip" from the moment the cartridge fires until well after the bullet is gone.

However, while the barrel is wiggling, there are brief moments when the barrel is indeed stationary, just as the barrel stops wiggling in one direction and before it starts wiggling in the other. That's when you want the bullet to exit and tuning the BOSS allows you to find that sweet spot.

Bart B.
October 13, 2012, 08:04 AM
Nobody, including Browning, has proved bullets leave at the top or bottom of the muzzle axis swing with the Boss set for best accuracy. One can adjust charge weight 1/10th grain and do the same thing as a quarter turn of the BOSS ring. And no powder charge makes pressure curves exact enough to make all bullets leave at the exact moment the muzzle axis is stationary

It has been proved that best accuracy is when bullets exit just before the muzzle axis reaches its highest angle which more easily and better corrects for velocity spreads.

natman
October 13, 2012, 09:40 AM
Nobody, including Browning, has proved bullets leave at the top or bottom of the muzzle axis swing with the Boss set for best accuracy. One can adjust charge weight 1/10th grain and do the same thing as a quarter turn of the BOSS ring. And no powder charge makes pressure curves exact enough to make all bullets leave at the exact moment the muzzle axis is stationary

It has been proved that best accuracy is when bullets exit just before the muzzle axis reaches its highest angle which more easily and better corrects for velocity spreads.

I'm not quite sure what point you are trying to make. First you say it's unproven, then you say it's proven. If you want to quibble about whether the best spot is "just before the muzzle axis reaches its highest angle" instead of standing still, please explain why. I'll grant you that while the muzzle is moving slowly just before it stops is easier to find than when it stops, but I don't see how it's better. Perhaps a citation to your proof would explain it.

Bart B.
October 14, 2012, 08:13 PM
Once one understands the ballistics for a given muzzle velocity in a 40 fps spread and the departure angle each needs for a given bullet to strike the same place on target, it is easy to figure out where in the muzzle axis vertical swing it's best for all the bullets to leave at. It ain't rocket science. Remember that lower muzzle velocities leave later than higher velocities.

natman
October 15, 2012, 01:39 PM
Once one understands the ballistics for a given muzzle velocity in a 40 fps spread and the departure angle each needs for a given bullet to strike the same place on target, it is easy to figure out where in the muzzle axis vertical swing it's best for all the bullets to leave at. It ain't rocket science.

It ain't any kind of science at all as far as I can tell.

Again, got a citation?

Bart B.
October 15, 2012, 03:01 PM
Skip the high level math formulas and look at the last page. That's the best part.

http://archive.org/details/philtrans05900167

On the left side, click on PDF in the "View the book" window.

Simple reasoning is that for slower bullets to strike the same place as faster ones, they all have to leave when the muzzle axis is on the upswing. No other part of the arc lets that happen.

derelict
July 22, 2013, 06:43 PM
Anyone using a BOSS equipped rifle for long distance shooting? Any adverse effects? I only really see reviews for people shooting at 100 yards or so. Im looking at an M1000 Eclipse in .300WM.

ripnbst
July 22, 2013, 08:25 PM
Anyone using a BOSS equipped rifle for long distance shooting? Any adverse effects? I only really see reviews for people shooting at 100 yards or so. Im looking at an M1000 Eclipse in .300WM.

True most people are zeroing at 1 and 200 yards but tighter groups are tighter groups. It applies at all distances.

Magnum Wheel Man
July 23, 2013, 06:09 AM
I have a stainless stalker in 338 Win Mag with a BOSS, that I'll be changing over from a hunting rig, to a longer range target gun over the next 6-12 months... the 4-16 Burris Posi Lock scope will come off, & a good long range scope added, with resettable to zero turrets... over the last year, I ended up getting over 500 new cases ( bought a 5 gallon pail at the local gun show, factory rejects that didn't have flash holes, ( which I've since remedied ) otherwise they are perfect, & of course unfired... so I plan on developing some good handloads for this cartridge, & will see how the Boss system works for longer ranges...

derelict
July 23, 2013, 04:01 PM
I figured that tighter groups are tighter groups but was hoping that there might be some feedback from people using them to take longer shots.

Is there any reason why the new X Bolt rifles do not come with this as an option? That is why I am asking. Im not a big game hunter anymore spending more time fly fishing than anything. I will take the odd trip West to see family and am a member of a long distance (500+ yard) range so Im looking for something with longer range ability than the .270 Ruger No. 1 I used to hunt deer around here (max shot was usually 80 yards).

I am really interested in the BOSS system since I really have no interest, nor the time, to hand load.


Are any of these Browning rifles having feeding issues with the WSM? I really wish they offered a traditional 7mm.

rdavidsonjr
January 26, 2014, 09:31 PM
Contrary to some reports it is neither a weight adjustment or a choke. It is a system that allows you to match the barrel to the load rather than the load to the barrel. Reducing the time consuming powder variations on multiple loads when building a load for a gun to group well. It is accomplished by micro adjusting the length of the barrel so that the bullet exits the barrel in the neutral plane during its harmonic vibration of which all guns do no matter how heavy the barrel is . Granted fluted bull barrels may be above average but they still vibrate. The neutral plane is when the barrel hesitates in the whipping which occurs many times during a shot.It is a matter of a given speed and time matching perfectly to the barrel. Also remember it takes the perfect steady hand to actually see these results. It does however tighten groups of a given round from say 1 1/2" to dime size and that is huge from 300 to 1000 yards. It is the difference between a hit and miss if you are steady ,calculate wind and elevation correctly. I am friends with 3 others besides myself and we are sold on the boss because we have witnessed the results.

rdavidsonjr
January 26, 2014, 09:38 PM
I have several guns without boss systems and I have to load several variations to find the best group.They still rarely compare to the groups with a properly adjusted boss. I last year purchased a 25-06 Thompson pro hunter thumb hole with a fluted stainless bull barrel. Love it, fits like a glove and gets great groups , but they still can't touch my 7 mm or 300 with a boss.

the blur
August 7, 2014, 12:36 AM
Can BOSS be added to a BAR, with out BOSS ?

Bart B.
August 7, 2014, 07:15 AM
Barrels don't hesitate (stop?) their whipping and wiggling until long after the bullets left. Where does any force counter to what keeps them doing that come from? It has to be external to the barrel mass that's moving from inertia.

Check out http://www.varmintal.com/atune.htm

Magnum Wheel Man
August 7, 2014, 07:26 AM
BART... your last post brings up an interesting thought... I'm wondering, if the stock were rigid enough ( like a premium composite ) & done in the full length style ( to the end of the barrel ), & the barrel fully bedded, not floated, do you think it possible to hold a barrel steady enough to make a difference, or would the wobble forces be so great, that it would "move" some place along the length, & thus negate the fully rigid concept ???

I do like my BOSS rifles, but just talking concepts at this point ( sorry to distract the thread )

Unlicensed Dremel
August 7, 2014, 09:27 AM
They had standard Bosses with a brake, and non-brake Bosses, IIRC, but you hardly ever see the non-brake Bosses, which would interest me more.

Mike Irwin
August 7, 2014, 09:48 AM
"Barrels don't hesitate (stop?) their whipping and wiggling until long after the bullets left. Where does any force counter to what keeps them doing that come from?"

The intent of the Boss is not to stop barrels from whipping.

It's to change HOW they whip; in essence, to use that whip to your advantage.


I've seen one person try the "fully bedded barrel" in a centerfire rifle, just as an experiment.

To say that it was an abysmal failure would be kind. It took a rifle that had been shooting a consistent 1.5" groups and opened them up to 4 to 6" groups.

Magnum Wheel Man
August 7, 2014, 01:04 PM
DREMEL... I was thinking about a spring clip, that could be spread enough to slip over the holes portion of the BOSS, that would spring back, & cover all the holes... or even like 3/4 of the boss, & could be turned independently, to cover the bottom 3/4 of the holes, so it would actually reduce recoil even more, & cut the sound through the holes by 3/4...

Freakdaddy
August 7, 2014, 01:40 PM
Can BOSS be added to a BAR, with out BOSS ?

No, at least that's what Browning told me when the BOSS first came out as I wanted to install in on my Stainless Stalker. Obviously, you could have a competent gunsmith thread the barrel to be able to install a BOSS system but what you won't have is the engraved hash markings on top of the barrel which is needed to fine tune it to your load.

It appears as though Browning is phasing the BOSS out (along with the A-Bolt being all but gone) so if you're wanting to get one new, your only option is the BAR Mark II Safari but it's only being offered in four calibers with this. I picked up a new 7mm Mag Safari with the BOSS just a couple of months ago as this caliber is completely being discontinued (this should be the last year) in this rifle and it's a rifle/caliber combination I've always wanted. Here's a link to the guns Browning no longer offers or the discontinued caliber offerings of certain models.
http://www.browning.com/products/catalog/firearms/finder-historic.asp

Bart B.
August 7, 2014, 03:00 PM
Here's how BOSS works:

http://www.varmintal.com/aeste.htm

http://www.varmintal.com/alite.htm

http://www.varmintal.com/atune.htm

http://www.varmintal.com/amode.htm

As long as bullets leave anywhere on the muzzle axis upswing, the velocity spreads they have will be fairly well compensated for. Slower ones leave at a higher angle, faster ones at a lower one. This is why many rifles with all sorts of barrel stiffness and lengths shoot the same load very accurate. The range band with the best accuracy may be at close range, medium or long range; depends on where on the muzzle axis upswing they leave at.

Make your own "BOSS" system by threading the first few inches of the barrel's outside to some fine-pitch thread count. Thread two or three nuts on the barrel then snug 'em up together different distances back from the muzzle. Shoot and move them as your heart desires.

Bart B.
August 7, 2014, 04:34 PM
Magnum Wheel ask: I'm wondering, if the stock were rigid enough ( like a premium composite ) & done in the full length style ( to the end of the barrel ), & the barrel fully bedded, not floated, do you think it possible to hold a barrel steady enough to make a difference, or would the wobble forces be so great, that it would "move" some place along the length, & thus negate the fully rigid concept ???Nope, that won't work. The barrel will still wiggle a little bit and bounce off the wood stock as you sort of explained. That'll change its vibration characteristics, just like a barrel rested on a fence rail hoping to nail a pasture poodle 432 yards away. People have tried full bedded barrels in fore ends only to learn the pressure against the fore end from holding and resting gets transferred to the barrel when it shoots. Best accuracy is cylinder bore; like unchoked shotguns.

You could use a 6" thick 24 inch barrel as it wouldn't wiggle very much at all. Or drill a hole in a 2-foot long six inch square metal block, then epoxy the barrel in it. That would stiffen it about 50% more than a 6" diameter barrel.

It's best to let barrels whip and wiggle all they want to and not bounce off anything doing it (that includes no epoxy pad under the barrel's chamber). It's very repeatable from shot to shot when they're totally free floated. And they're probably the most repeatable part of the shooting system.

Unlicensed Dremel
August 7, 2014, 06:22 PM
MWM, yeah, there are brakes built similarly to what you describe, where they can simply be "turned off", but I believe the Boss system was all or nothing - either a brake Boss or no-brake Boss. I could be wrong. Never had one.

Bart B.
August 7, 2014, 07:13 PM
derelict asked if BOSS systems were used on long range rifles.

I've never seen one in a long range match, but they would work. Benchresters sometimes use them on their short range rifles. But when one uses reloads, they'll often tweak the powder charge for best accuracy at long range. The British Commonwealth long range competitors liked the SMLE because it compensated very well at long range with the cordite loaded arsenal ammo they had to use. The SMLE's shot more accurate with that ammo (huge velocity spread) at long range than a Mauser 98 action rifle did, but the Mauser out performed them at the shorter ranges with the same lot of ammo. It's all about barrel whip angle and muzzle exit timing of the bullets.

They're often used by smallbore rimfire rifle shooters; it really works with them because they cannot adjust the powder charge for best accuracy. That's usually easier than trying out a dozen or more lots of ammo trying to find one whose muzzle velocity is in tune with the rifle's barrel whip frequency.

Catfishman
August 9, 2014, 06:14 PM
Do you wear hearing protection when you hunt using the BOSS?

jgcoastie
August 9, 2014, 06:52 PM
No, but if you need a follow-up shot you'll wish you had some...

Catfishman
August 9, 2014, 09:20 PM
Most paired organs aren't tough. I think I'll leave the muzzle breaks alone.

saands
August 10, 2014, 10:05 AM
The one that I made for my 243 didn't have the brake and it was great. I have never used a real BOSS, but it is also my impression that they were full-time brakes or full-time not. As for hearing protection ... I have found that braked rifles are almost always louder, but the extent to which the punishment goes to the shooter or their buddy varies between designs. The BOSS should be used for long range because it allows you to shoot the fastest loads your rifle is capable of and tune the harmonics so that those loads are the accurate ones. People will say "It's only 75 fps" but 75 fps makes a difference when you are pushing a cartridge all the way to the point where it goes trans-sonic ;)

Saands

Bart B.
August 10, 2014, 10:43 AM
The BOSS should be used for long range because it allows you to shoot the fastest loads your rifle is capable of and tune the harmonics so that those loads are the accurate ones.I disagree if you're going to use handloaded ammo. Adjust the powder charge for best accuracy. There's typically a one grain spread in charge weight where best accuracy won't change. And some recipies will shoot very accurate and equally well at long range in several barrels' different profiles and lengths.

saands
August 10, 2014, 10:59 AM
Bart,

If you are shooting well within the distance capabilities of your cartridge, then I agree that there isn't any reason not to just adjust the charge to get accuracy (except maybe if you are using one of those crazy barrel burning calibers that only give you 750 rounds of barrel life ... in my experience, the BOSS tunes with far fewer rounds than it takes me to tune a load to a rifle). If, however, you are pushing your caliber all the way to the point where it goes subsonic, then the extra velocity that the BOSS might give you (not every rifle happens to like max loads) could make the difference between arriving supersonic and stable or arriving in the transonic region. Even most long range shooting isn't right at the edge, so the BOSS might be considered a niche tool and certainly isn't for everyone ... and it IS one more thing that can come loose if you aren't paying attention :eek:

Saands

Bart B.
August 10, 2014, 11:33 AM
however, you are pushing your caliber all the way to the point where it goes subsonic, then the extra velocity that the BOSS might give you

How does the BOSS give more velocity to a given barrel?

saands
August 10, 2014, 12:08 PM
How does the BOSS give more velocity to a given barrel?

A normal barrel will typically have a few accuracy "nodes" (muzzle velocities that yield the best accuracy). These nodes correspond to velocities that put the bullets at the muzzle when the muzzle is at an extreme deflection. Because the speed of the muzzle is at a minimum at max deflection, small changes in the load don't lead to large changes in the point of impact. This makes for nice small groups. Where the BOSS helps is that these accuracy nodes rarely happen at the max load in a normal barrel ... sometimes they do, but not often. When you tune the barrel harmonics with a BOSS, you change the velocities of the accuracy nodes. So ... while the BOSS clearly doesn't add velocity to the barrel, it can (and usually does) allow for higher velocities to happen at the same time that max accuracy is also achieved. So, if optimum accuracy is a constraint on your loads, the BOSS will let you run at higher velocities most of the time.

Saands

Bart B.
August 10, 2014, 12:48 PM
Is that maximum muzzle deflection when the muzzle axis angle is at either extreme from when it's straight out in a static condition and at either extreme of angular displacement due to the barrel bending from shock from firing?

Has Browning always bedded BOSS equipped rifles in hard rubber urethane?

saands
August 10, 2014, 02:52 PM
Yes ... the shock from firing initiates the vibration ... the frequency of the vibration is going to be the resonant frequency of the barrel system. To the best of my knowledge, Browning has always used Flexane 80 (or 85) ... at least that is what they disclosed in their patents. The Flexane will actually attenuate the vibration a little. It's kinda messy stuff to use, but it does work.

Saands

Bart B.
August 10, 2014, 03:27 PM
A 30 caliber 30 inch long 5.1 pound Palma barrel or a 26 inch 4.4 pound heavy sporter barrel is not as stiff as a 22 inch long 2.1 pound featherweight 30 caliber barrel. That Palma and heavy sporter barrels resonant frequency is about 39 Hz while the featherweight one's 64 Hz. They go through one 360 degree whip cycle in 1/39th or 1/64th second.

Typical barrel time for most bullets is 1/800th to 1/900th second. Bullets leave the barrel long before the muzzle axis moves 90 degree down which is its first direction with conventional stocks.

How is it possible for a bullet to leave at an extreme muzzle angle at those resonant frequencies in the range in what most barrels have?

saands
August 10, 2014, 09:08 PM
A 30 caliber 30 inch long 5.1 pound Palma barrel or a 26 inch 4.4 pound heavy sporter barrel is not as stiff as a 22 inch long 2.1 pound featherweight 30 caliber barrel.

I'm not sure where you got your stiffness and resonant frequency values, but it seems very counter-intuitive that the skinny barrel is stiffer than the heavy barrel. Also, the values of the resonant frequencies seem awfully low. When you whack a barrel (of any shape) with a hammer, the sound it makes is not that of deepthroated tenor, it sounds like a high pitched "piiinnnnnng" ... It's getting to be bedtime here, but tomorrow I will grab my Roark's Handbook and run the numbers on a barrel. One last thought is that maybe it is the higher-order harmonic that we are hearing and if so, then it would be those that would be affecting the accuracy. I'll let you know what I find.

I will say that if your numbers are correct, then you are making a VERY good point.

Saands

saands
August 10, 2014, 09:17 PM
Just did a quick calc on a 1" thick piece of steel that is 20" long (those numbers were easy to run) and its resonant frequency is 16kHz ... the first harmonic is just a tad more than 100kHZ ... Since the resonant frequency varies with the square root of stiffness/mass ... the tube's numbers should be even higher.

More to follow ...

Saands

Bart B.
August 11, 2014, 07:27 AM
In your calculations, be sure the bore diameter, the barrel's profile and section taper lengths and diameters are correct. Use fixed breech end formulas as barrels alone in space have different resonant frequencies than those screwed into receivers solidly affixed to the stock.

The high frequency made by sound waves bouncing back and forth (traveling about 16,000 fps in type 316 stainless steel) are not what barrels whip like fishing rods do when casting lures. Rods and barrels fixed at one end whip at very low frequencies typically under 100 Hz. Example below:

http://www.varmintal.com/amode.htm

There's other examples on his web site.

I'll use the software I asked Tom Irvine's company to make (rifle frequency) below:

http://www.vibrationdata.com/updates.htm.

to calculate a 24" long barrel weight and resonant frequency for a barrel dimensioned as follows:

1.2" dia. x 2" long reinforce (1" long tenon in receiver not used)
1.2" dia. x 2" long x .9" dia. taper
.9" dia. x 19" long x .6 " dia. main taper
.306" bore dia. (.0736 square inch area typical for 30 caliber)
316 stainless steel
Breech fixed

Chamber volume not used. If used, resonant frequency will be a little less. We can compare results. They should be very close, if not the same. Note that the mass of the stock and scope attached to the barrels breech end will alter frequency calculations because they're part of the whole rifle that wiggles when fired. It's best to assume a solid mounted receiver to see what the barrel alone vibrates at when fixed at its breech.

First study on a barrels low frequency vibrations in the vertical plane was made over a century ago. Enjoy the math but the last page is the overall conclusions:

https://archive.org/details/philtrans05900167

99% of all the rifle barrel vibration stuff on the internet is bogus babbling developed to satisfy an incorrect assumption. It's well understood that slower bullets have to be launched at a higher angle than faster ones to strike the same place on target. The only part of the vertical muzzle axis swing that does that is the upswing. It's impossible if bullets leave at the extremes where the axis reverses as half would leave on the upswing and half on the downswing due to normal spreads in barrel time and muzzle velocities.

Fluted barrel stiffness blasphemy is common, too.

F. Guffey
August 11, 2014, 09:18 AM
Then there was the Model 70 with the bulge in the barrel. About 8 years ago there was the 'dog knot', it was the rage, just slide it back and forth to obtain the sweet spot?

Then there is the ugliest rifle ever "sporterised". I did not think anyone could build something that ugly without knowing more than his critics...about guns. I bid and won the auctions, $120.00. I went to the range with 12 different loads 10 rounds each. After firing all the ammo over a period of a day I applied the leaver policy, I decided to leaver the way I purchased-er. the rifle was purchased for parts, not easy to build a rifle with a better predictive accuracy.

F. Guffey