Wildcat! Something New For Me

[GWS]

I've always owned factory rifles chambered for factory cartridges, for which I reload using published data from powder and bullet manufacturers.

I recently adopted an old FN (1951) Mauser, rebarreled and chambered for a wildcat cartridge......namely .22-243 Winchester. This wildcat is simply a .243 win necked down to .22 (.224). Same shoulder angle same length as a .243win.

So therefore there is no published load data excepting that posted by individuals. and that's rare, and questionable.

Now then, I bought a set of Redding Full Length Dies for this caliber (yes they make one....so does RCBS), and I sized a few. Then I cut some closed-cell foam circles and filled the primer pockets tight enough to hold water, filled them with water and weighed both empty and water filled cases.

I even have some LC 1968 cases that I necked down to .243 years ago and decided to neck a few of these also down to .22-243, and weigh.

So here's the average results:
Federal cases hold 53.8 grains of water
LC 1968 cases hold 51.2 grains of water

Now looking at a published list of factory cartridge volumes I discovered that .223 WSSM hold 53 grains of H20 on average.

So here's my question: Wouldn't it be reasonable to use published Hodgden start loads for .223 WSSM for this wildcat cartridge and work up? Or am I missing something important!! (of course less for the thicker LC brass perhaps .220 swift data since they hold 48 grains of H2O). I plan to start with 55 grain bullets. Barrel twist is 1-14.

This ought to be a real laser of a rifle. Yes, a barrel burner if one gets carried away, just like the .223 WSSM. What's the thinking here? I want to be safe.

[green_MTman]

we can safely say that the powder charge for a .243 using a 100 grain bullet would be safe in the 22-243 using 45,55 gr .22/5.6 mm bullets.

so try the maximum load for say a 100 gr .243 bullet as your start,then very slowly work up untill you see subtle signs of high pressure.then stop and back off a grain.

best i can see.also the .243 is not that far from a .250 sav so you may want to check 22-250 loads too.

[Jim243]

Well, that is a horse of a different color. (LOL)

I load for both 243 and 223. The problem using 243 load data will be the smaller dynamiter of the 224 (223) bullet. More friction and less weight.

I have a load for a 65 grain Hornady V-Max I use for the 243 of 39.0 grains of H-4895 with an OAL of 2.600. That should work in your 22-243 without any problem.

If it was me, I would start with the load data for the 243 and a similar weight 223 bullet at the lowest starting powder and work up from there.

Good luck and stay safe.
Jim

Wouldn't it be reasonable to use published Hodgden start loads for .223 WSSM

No, completely different size case. I would be concerned about too much air space in the 243 case and developing an over pressure round.

[Rockchucker333]

I may be able to get my hands on some load data for you from a very reputable man. He is elderly and hard to contact but I know he had a wildcat chambered like yours. Never saw him shoot it but I inow if he had it he hand loaded for it. And with him it was a ragged hole 100 yard shooter or he wouldn't have kept it. Let me do some digging this weekend for you my father and I are doing to visit him.

[jdscholer]

Aside from the powder charge question, I would difinately check loaded neck diameter with your necked down brass to make sure you don't need to turn your necks to have a good fit in your chamber.

Frankly, I'd start with a chamber casting before I got carried away about anything. Wildcat/custom chambers can be -- different. You don't want a situation where your are essentially crimping your bullet in the case when you close the bolt. jd

[Unclenick]

CAUTION: The following post includes loading data beyond or not covered by currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.


GWS,

Regarding differences with the WSSM, it has a maximum average pressure rating of 65,000 psi vs 60,000 psi for the .243 Win. I presume the wildcats will be rated as the latter, since they use the .243 case. You can expect what QuickLOAD calls the Weighting Factor, the percentage of powder and gas pushed down the barrel with the bullet, to differ with the size of the opening and the shoulder angle, and that does affect peak pressure. QuickLOAD gives the WSSM a weighting factor of 0.5, and the .243 a weighting factor of 0.65. If I change the .243 Win between 0.65 and 0.5, it has about an 8% peak pressure value effect.

The WSSM has an 8" twist, while you have a 14" twist. That can raise the WSSM pressure a bit just due to the faster twist, but I wouldn't count on it as a tweaking factor for your gun. I will say, though, that I've had less than stellar results with 55 grain bullets in 14" twists, so I would probably be starting with a 50 grain flat base bullet of some kind.

If I were working out the load, I would take WSSM load data for my same bullet, and knock it's maximum charge value down 15% to have some wiggle room for the lower peak pressure and the possible difference in weighting factor. I would be careful to use the same seating depth if it is compatible with your gun's freebore and throat position. This is so the bullet subtracts the same amount from the powder space in both cases. The seating depth for the WSSM is found using the load data's COL as:

Seating Depth = Case Length + Bullet Length - COL from load data.

For the WSSM, the case length number to use is 1.670 inches.

For your cartridge, you want to rearrange the above and take the above seating depth result and use it to find the COL it produces in your cartridge. That would be:

COL for your wildcat = Case Length + Bullet Length - Seating Depth from WSSM calculation above.

This load should come up light, but very safe. You would work up from there watching for pressure signs.

[603Country]

I thought I remembered seeing a 22-243 in PO Ackley's book. Went to look and I find that the OP has what was once called a 224 Durham Jet, which was apparently originated by Charles Durham.

The 224 Durham Jet may be slightly different from the OP's wildcat due to shoulder angle. The Durham Jet shoulder angle is/was 40 degrees. In a 22.25 inch barrel and a 12 inch twist, load data shown has a 55 gr bullet over 46 grains of H380 for 3960 fps. A 63 gr bullet over 46 gr of 4350 shows a mv of 3710.

I'm not suggesting that the OP use these loads, but am only showing data originally offered by Mr Ackley.

[GWS]

green_MTman we can safely say that the powder charge for a .243 using a 100 grain bullet would be safe in the 22-243 using 45,55 gr .22/5.6 mm bullets.
....
best i can see.also the .243 is not that far from a .250 sav so you may want to check 22-250 loads too.

Yours was my first thought until I also came up with what Jim243 said:

The problem using 243 load data will be the smaller dynamiter of the 224 (223) bullet. More friction and less weight.

The water nozzle effect....smaller hole more pressure. I also thought of using 22-250 loads but that's a smaller case and leaves a lot of empty space. Too much empty space can cause detonations unplanned for. (as in light loads too light)

Jim243 says no to .223WSSM, completely different case size (and he's worried about the "space" factor too. But actually while it is a different case "shape" the volume inside is almost exactly the same as my Federals, as I found with my water volume testing.......and......the neck diameter is the same as well.

jdscholer brings up 2 points I've also been working on.

jAside from the powder charge question, I would definitely check loaded neck diameter with your necked down brass to make sure you don't need to turn your necks to have a good fit in your chamber.

Frankly, I'd start with a chamber casting before I got carried away about anything. Wildcat/custom chambers can be -- different. You don't want a situation where your are essentially crimping your bullet in the case when you close the bolt. jd

I am ordering an outside reamer pilot. But as for a chamber cast, I did get 20 cartridges with the gun....unknown reloads obviously. They chamber perfectly, but I'm not about to shoot one. I took one apart: 50gr. flat-based spitzer, with what appears to be 4064. Very large "logs" IOW's Obviously I can't be sure. The cases are as I described, in fact I thought I was getting a .243 until I tried chambering a factory .243. Yeah lots of rolling eyes here!

BTW, if I may ask, what material is normally used to make a chamber casting? Never done one before.

603Country, I've researched .22-243 for weeks and never came up with the 224 Durham. That's a new one. Popular derivitives are the .22-243 Win., .22-243 Middlestead, and the .22-243AI. Less popular is the .22 Cheetah that uses .308 benchrest (small primer) brass. All have more abrupt shoulders than the one I have so I'm assuming it has to be .22-243 Win.

Unclenick!, Thanks for your time. You gave me some food for thought on the potential use of the .223WSSM. The pressure rating of the brass & difference of shoulder angle. The size of the opening is the same at least. 8% peak pressure delta is good to know. And yes 8" vs 14" twist is different, but less twist is a plus for me...less pressure. May not be a tweaking factor as you said, but it certainly is a comfort factor the right direction.

As for 55 grains. I've been told that the 14" twist will stabilize up to 60 grains in this caliber by those who use them. I planned to test 40-60 grain bullets but I figured 55 would be my start, and if not stable enough that would also eliminate 60. Yes I'm pretty sure 50 grain will end up being the goto.

Knocking down the start load 15% may be prudent. Thanks for the suggestion, that and seating depth. I'll add those to my checklist.

Thanks, for all the posts! Rockchucker333, yes I would be interested in the gentleman's data if he still has some. thanks for the effort! I will update this project for a while. Somebody else may run into a similar thing down the road.

BTW, I'm told this performs similarly to the Swift, but typically 100fps faster with all bullet sizes! More than a few have gone down this road but not documented it well for others. Those who shot out barrels typically replaced them with a faster twist version and loaded them up to 80 grain bullets with very pleasing results. (and perhaps even faster barrel burnout?) Anyway it's interesting.

On another note, my project gun was an unfinished project. The magazine was still original for 7mm Mauser cases and wouldn't feed the .243 sized cases. I've fixed that problem....it took me (gunsmithy challenged) 2 months to gather the info and carefully open the magazine to feed "short-fats" as one Mauser gunsmith called them. Success finally as the video demos below. Should be interesting to shoot it.

https://www.youtube.com/edit?o=U&video_id=cbsdBldk2zk

[603Country]

GWS, I'd be very surprised if your rifle didn't shoot the Sierra 63 grain SMP bullet. That one is good and short and shoots great in my 220 Swift.

[jepp2]

BTW, if I may ask, what material is normally used to make a chamber casting? Never done one before.

Cerrosafe link, melts between 158-190 degrees F. I gave the link for MidwayUSA, but I bought mine slightly cheaper from a metals company.

Just for information, QuickLoad version 3.8 does have your cartridge listed, so that is where I would start with calculation for loads. QL shows 55.0 gr WC but you can change that to your actual "fired" cases.

[GWS]

Thanks for the Link.....sigh....one more thing to buy!

603Country, I will put that bullet on my list to try. They have really come up with some interesting bullets that perform well out of their elements....maybe that is one of them. Thanks for the heads up.

[603Country]

GWS, with a 1 in 14 twist, the heaviest bullet you will most likely be able to stabilize is that 63 grainer. At least that has been my experience. Maybe, just maybe, the 60 gr Nosler Partition will stabilize, but it's a bit longer and would only shoot in my rifle in warm weather. And try though I might, neither the 64 gr Nosler Bonded Solid Base nor the 65 gr Sierra Gameking would stabilize. Both are too long. At least the 64 grainer hit paper at 100 yards. I have no idea where the 65 grainers went, but it wasn't to the target.

[GWS]

Thanks for suggesting a chamber cast. I did a partial cast with epoxy putty over a case and discovered I bought the wrong stupid dies......Shouldn't have based the buying decision on the loaded cartridges that came with it! Obviously! Nuts!



So it isn't a .22-243 Win with a 20 degree shoulder after all, but looks like the .22-243 Middlestead with a 30 degree shoulder as pictured below!



Still I will order some Cerrosafe tomorrow....and take a full cast to make sure it's not a .22-6mm or something. I'm wondering why he had the cartridges.....unless he sized them .22-243 Win. and then fire-formed them to Middlestead.

The next photo is of the 22.243 AI with its even more radical 40 degree shoulder angle....so I know it's not that one.



Well.....the silver lining is....at least this gives me a longer neck! That's good, at the expense of slightly reduced capacity.

The reason I did the partial cast before the Cerrosafe arrives, it because I mounted a bullet to a Stoney Point (modified to work like their modified cases) and tried to measure to the lands.......stupid bullets were pushed clear off the cases, so I knew I had a problem. Deep throat! Nuts, again!

One other thing I learned from the partial cast: the neck in the chamber measures a generous .262". Looks like I don't have to ream or turn necks. But a new .22-243 Middlestead sizer is needed.

[jdscholer]

One other thing I learned from the partial cast: the neck in the chamber measures a generous .262". Looks like I don't have to ream or turn necks.

Yeah, hopefully that's the case, but be aware that various substances have considerable shrink/expand properties, including the Cerosafe chamber cast metal. (it continues to expand after casting for several hours, and must be measured one hour after casting.)

I recently acquired a rifle that required this process, and now wonder why I haven't messed with it sooner. It is cool, fun, and informative to do. Gives you a great perspective on chamber dimensions, shoulder angle, neck diameter, throat length, -- all the stuff that we usually guess about and never quite know. jd

[GWS]

Yes, I read that about Cerrosafe. Interestingly this epoxy putty in a tube (white underwater stuff) from Home Depot worked quite well and was stable dimensionally. 12 hrs later and it still chambers and still measures the same. The only down side is it would be hard to fill an entire chamber with it, being in putty form....as it was I couldn't get it to go all the way into the lands so I still don't know where they are.

So if I were to fire-form the rounds I load with the .22-243 Win sizer, I might make things worse. The potential problem I see:

1.The existing brass with the 20 d. shoulder chambers easily....which means the shoulder/neck intersection is where it touches first in the chamber if allowed to go all the way in.

2. That in turn means the beginning of the case shoulder is not allowed to go all the way to the chamber shoulder, and allow the case neck to be longer during fire-forming) being held back by the extractor.

3. That would indicate that the fire-form reshaping of the shoulder would grow it forward, leaving the case neck short. Right?

4. Therefore the whole case would be short and the bullet would be barely seated and still be nowhere near the lands. Nor would the neck fill the front of the chamber except as it stretches. Doubt it will stretch a quarter inch.

[jdscholer]

3. That would indicate that the fire-form reshaping of the shoulder would grow it forward, leaving the case neck short. Right?

Ummmmm-- I don't think that is necessarily so. You just won't know till ya try.

You may be overthinking/worrying this thing too much.

I would full size a cartridge with your FL die, check trim length, seat a bullet, and see if it fits well with no tightness especially in the neck region.

If everything is peachy, load up a safe couple of cartridges with a powder such as 4895 or 4320. Extrapolate charge weight from researching appropriate cartridges/sources, and go fire-form a few.

You have checked your bore dia. haven't you?? It would suck to find out you actually have a new .20-243. jd

[GWS]

You may be overthinking/worrying this thing too much.

I would full size a cartridge with your FL die, check trim length, seat a bullet, and see if it fits well with no tightness especially in the neck region.

If everything is peachy, load up a safe couple of cartridges with a powder such as 4895 or 4320. Extrapolate charge weight from researching appropriate cartridges/sources, and go fire-form a few.

You have checked your bore dia. haven't you?? It would suck to find out you actually have a new .20-243. jd
jdscholer is offline Report Post

So, you are suggesting I make some ammo with my existing .22-243 Win sizer and just see if it fire-forms right? I can tell you that I have (minus primer and powder) and it chambers without even a little extra effort. No squeeze in the neck, period. But since that's true I think the shoulder has to move forward....I know the bolt won't. That's why I'm hesitant.

What do the rest of you think? Anybody experienced in fire-forming forward? Could you really expect the neck to grow, or just the shoulder to bolt face to grow to fill the space in front of it?

As for my bore, the free space after the neck and before the lands measures exactly .22" dia. and at least .360" long. I haven't managed to reach into the lands with the epoxy yet. Already seems a bit long for a 1-14 twist and the short .30 to .60 grain bullets that suggests. (but I'm no expert at making barrel chambers for sure!)

[jdscholer]

GWS, you are correct to be hesitant, and I think I'll take back what I suggested, as far as fire-forming goes. I still recommend casting the chamber to remove any doubt.

It seems that if the Middlestead version is created by pushing the shoulder back increasing the angle and lengthening the neck, that your low angle cases would pinch at the junction of the neck and shoulder. If as you say, they don't, -- well, -- more info is needed, and a chamber cast would be a good place to start.

Here's a page on the 22-243 Middlestead if you haven't seen it. http://www.accuratereloading.com/22-243.html

And here's a link to a pretty good deal on Cerrosafe casting metal.http://http://www.ebay.com/itm/Cerro...item462292d843

This cartridge interests me for a particular reason. I have been busy lately with a rifle chambered in 22 BR, confronting some of the same questions you've got with my very tight custom chamber, and if I ever get tired of buying dollar apiece brass, or wear out the throat on this chamber, the 22-243 would be a good next step for this barrel. jd

[GWS]

I ordered some Cerrosafe, and a new Middlested die set from Grafs.....They, Graf & Sons, came through.....I have a return number to return the other dies. So far a good day.

Hoping the Cerrosafe mold doesn't ruin another day. Not sure about the length of the throat.

Thanks for the suggestions.