.223 Rem Wildcat?

[ThatGuyHank]

Just a quick question; I was doing some thinking the other day (dangerous, I know) and I was wondering if anyone ever cut a .223 remington case at the beginning of the shoulder and topped it with a .355 caliber bullet? It seems like it'd make sense: use the natural dimensions of a parent case to make something different. The idea sounded funny at first but my research doesn't really come up with anything conclusive.

I'm curious why it appears nobody has tried something like this yet? Is it too many cartridges exist that would function similarly that it would be a futile experiment? Or maybe there is some critical detail I'm missing that would make such a creation impossible/improbable.

 

[mljdeckard]

.300 blackout?

 

[swampcrawler]

I know that a lot of stuff has been done with 233 brass but I'm unaware of a 35 cal wildcat. It should give you pretty much a rimless 357 Max. Which would be awesome.

 

[KansasSasquatch]

Not exactly what you're asking about but very close http://en.m.wikipedia.org/wiki/300_AAC_Blackout_(7.62×35mm)

 

[ArchAngelCD]

.300 blackout?

And or .300 Whisper?

BTW, no reason to cut the case at the neck thus reducing case capacity when you can neck-up instead.

 

[oldpapps]

Don't want to rain on your parade but.

.223 Rem chambers and cases are a slight taper. Yes at the shoulder the outside diameter is .335 inch (chamber) and .3542 inch (case) but just .4338 inches back in the chamber and on the case, that outside diameter has expanded by .0041 inches and .0042 inches respectively. Doesn't sound like much until we start determining where to get case tension to secure the bullet.

Next problem is where/what do we head space on? The case is rimless so that is for the most part out (yes a rim hook could be devised, unsound option to me). Head space on the case length like the 9MM (and others, this would be a super long 9MM round), great except with the minimal at best neck tension, I feel this would be a very poor option, way too temperamental. Last option I can come up with would be to use the case taper similar to the .30 Carbine and M43 7.62X39. I don't think there is suitable taper for consistent head spacing.

As I am far from being a mechanical wiz or an engineer, my views are questionable and possibly laughable.

To me, neck the case to provide a set point to head space to. But we have the many versions of that including the SAAMI accepted standard .300 AAC Blackout.

Good luck. You could very well come up with a winner.

 

[JT-AR-MG42]

Like oldpapps mentions.

Even blown straight (the .223 measures only .375 at the base), the case would need inside neck reamed to place a .355 bullet.
If you were able to do so, I don't think there would be enough brass left at the mouth to provide tension on the bullet.

If you google the case dimensions on the .351 (with it's smaller diameter bullet) and compare it to the .223 case, you'll see the situation.
IIRC, .338 is about the largest you can go with a blown .223 and have a selection of commercially available bullets.

JT

 

[Dframe]

What you've described is much like the "Super 9" created by the late Jeff Cooper. Though I believe he shortened the case more and modified the extractor on his pistol.

 

[Jim Watson]

CotW shows a .338x223 that headspaces on the case mouth in the manner of a straight rimless pistol round.

 

[ThatGuyHank]

No parade to rain on, just kind of thought about it while staring at cases. I looked up a cross section of the .223 and I see the problem with the case thickness; that does not seem like an ideal situation. Perhaps there is a better suited parent case for such a venture?

 

[oldpapps]

"Perhaps there is a better suited parent case for such a venture?"

Not a cloud in the sky.

What about using the BCG from a 6.8 weapon. The base cartridge is the 30 Rem and if shortened could very well provide a neck that would hold a .355 to .357 bullet. Feeding could well be a problem with stubby pistol bullets.

It would be an interesting project. Could very well make a short range sub-sonic as well as a stomping short range sonic round. I wouldn't expect it to keep up with some/most of the existing AR chamberings.

Got to keep thinking and maybe......

 

[ThatGuyHank]

After doing some looking, I found .308win cross sections and dimensions. It does not appear to have the same taper problem the .223 has. Perhaps blowing the neck out to .40 or even .45 caliber seems possible. I'm not entirely sure why but I like the idea of a large bore round with more power than a pistol but isn't thumping and could potentially fit into a smaller package.

 

[oldpapps]

The same Mauser head type is used for bunches of cases including the .45 ACP. So, an AR in .308 could be barreled in .451/.452 and the 308's 52 MM length utilized for a lot of propellent. I would think that the mechanical limitations of the action would limit the potential and even with that limit, it would/could be a bruiser.

I always wanted to re-barrel a SMLE from .303 Brit to .429/.430. The SMLE 10 round detachable magazine could easily be shimmed to place .44 Mags in place to feed. The .303 Brit has (almost) the same head. But, you are looking at auto loaders not bolts.

Keep thinking, there are lots of possibilities.

 

[swampcrawler]

^^and thanks to this dude I now want a Mauser in 45 acp.

Or any bolt rifle, even single shot in 45 acp. Just because it'd be fun. Lol

 

[oldpapps]

Interesting, we have gone from the .223/5.56 to the Mauser head in a .45 ACP case.

I have a Marlin Campgun in .45 and moving from my standard 5 inch barrel to the longer 16 1/2 inch barrel and (using the same loads) only get an increase of 143 fps. Hardly worth the effort. (Yes, I could run a process to utilize the longer barrel. I don't think I will.)

The big reason I have not pursued the .44 Mag in a SMLE is cost. There are lever guns that meet that need for a lot less money.

Keep on thinking. That is a lot of the enjoyment.