AR 15 wildcats

[michael5446]

spent the last couple years looking over all the different AR-15 cartridges that have cropped up... wow! i would like to try all of them, but i cant...
been working on this one, the .40 carbine... i have read many posts over several forums if this cartridge exists, it may, but nobody has mentioned it...is any body out there working on this one?

what would be the advantages of a cartridge like this, designed for 155 to 200 bigger bore pills that truly double stack in standard ar mags....

would you be interested in developing this one as an online popular project, can we do it?...
below -- .450 bushmaster , 7.62x39 , proposed .40 carbine

IMG_0254.jpg (64.92 KiB) Viewed 11301 times

[Siringo]

I would like the 40. This must be a 308 case? What about putting a shoulder on a 450? I know it would not double stack, but it would be a screamer

The 200 grain SST Hornady MZ bullet (40 cal) would make a true 300 yard carbine. I tried this bullet using a sabot in the 450 case-- but it did not get the results that I was hoping for.

What I would like to see, based on the 450B case of 284 case, is a 338 or 35.

I think the answer to your question -- YES!

[Siringo]

One more think -- we need a better bolt. Something line AR15 Performance is making.

[michael5446]

glad to see some interest by one so far, a .308 case is to short for this app... but common brass from a once popular cartridge works great with minimal work, a .308 bolt would work though... so far the .40 reload dies work great with little effort... i have a barrel on the lathe and can use standard chamber reamers...

the idea here is to get big bore performance and change nothing to the .223 ar format and have the rifle/cartridge/mags work 100% true and cheap , which the 450, 458 socom, and beowolf, 9mm, .45, 6.5 and countless others in my opinion do not...

i dont recall ever seeing a cartridge developed online, i would like to see this one of the first... thanks Siringo, keep the ideas coming people!

[2zero6]

Interested and subscribed!

[wildcatter]

Mike,

I have some things in the works, but the .40 carbine cartridge, you show, has a parent case, do you know what it is?

..t

[Siringo]

If I guess right -- what do I win? 7 x 57 Mauser.

[oldmanjeffers]

I want to play!

30-06....

[thebrassnuckles]

I had thought of this a while back when I first picked up my 450. here are my thoughts..

I think a shoulder would be beneficial in that it would eliminate the need for a LeGendre type side crimp that could, if improperly applied, have a negative effect on accuracy.

The downfall of a shoulder would be reduced magazine capacity.

I feel that the rifle should use pistol caliber bullets, so it can take advantage of both pistol ad rifle bullets, after the rifle bullets are resized of course, much like our beloved 450...

I dont know how much you can resize a bullet, but there are numerous listings of .400-.412" handgun bullets on midwayusa .

the majority of .40 caliber rifle bullets are .408" and abouve. the smaller diameter bulets are mostly made from lead, so likely there would be a similar situation with the 450 and lead bullets on the new cartridge.

[2zero6]

I had thought of this a while back when I first picked up my 450. here are my thoughts..

I think a shoulder would be beneficial in that it would eliminate the need for a LeGendre type side crimp that could, if improperly applied, have a negative effect on accuracy.

The downfall of a shoulder would be reduced magazine capacity.

I feel that the rifle should use pistol caliber bullets, so it can take advantage of both pistol ad rifle bullets, after the rifle bullets are resized of course, much like our beloved 450...

I dont know how much you can resize a bullet, but there are numerous listings of .400-.412" handgun bullets on midwayusa .

the majority of .40 caliber rifle bullets are .408" and abouve. the smaller diameter bulets are mostly made from lead, so likely there would be a similar situation with the 450 and lead bullets on the new cartridge.

Would we be able to use curved magazines to increase capacity because of the shoulder? Also would it be possible to resize the plethora of .416 projectiles?