wildcat 40 cal AK
Been a while since I've been on Gunco...2009 or so. I figured I'd come back with a bang, though.
This is one I started a year ago. It's been through various designs...and redesigns....and redesigns. I wanted to do a 40/10mm wildcat. I originally was just going to do a 10mm mag, but I wanted a bit more bang. My goal is 2200 fps with Hornady 200 gr XTP bullets.
I first started looking at chopping down either carcano or 8mm mauser brass. Both of these will take a 40 cal bullet when cut just under the bottleneck. The 8mm was the best one and I formed several brass @1.75" OAL. It's easy to make, but I just wasn't sold on something that headspaces off the casemouth for this project. I looked at doing off the shelf 450 bushmaster and various other calibers, but I wanted something unique that had readily available brass.
Next up I tried forming 308 and 30-06 brass into something resembling a 300 BLK, but in 40 cal. The 30-06 looked great on paper, but was a real bitch to properly form the brass and have a consistent shoulder formed. I was playing around int he garage and had a bag of 300 WM brass there and decided to mess with that. I cut it down to 1.8" and crammed it into my rouged out forming die. I crushed the shit out of the brass....but overall I kind of liked where it was going. I made a reamer, cut a forming die and did it right this time. I really liked the results!
The funny thing is...after a year of tinkering and calculating various options, dimensions, case capacities, etc...I ended up with a 40 cal version of a 458 SOCOM. I'm just a hair longer in OAL, but other than that, it's just a few thousandths different! The main difference is that I'm using a belted mag case and the 458 uses the non-belted base. I could actually make my cartridge from 458, but I don't want to for a couple reasons.
I actually like the idea of headspacing off the belt better than the shoulder.
I can get 7mm or 300 mag brass for a fraction of the cost of 458 or 50 B brass!
The weapon uses some stock AK parts and I want the .447 rim dia. The 458 is trimmed to a 5.56 cartridge dia and is too small.
So here is where I'm at:
A heavy barrel being made from a Green Mountain blank.
Chamber reamer is being made as are new reloading/case forming dies.
Custom made gas block and front sight.
Custom Wood made from red heart and agarita (radioactive themed weapon).
Custom top cover that will pivot off gas block/front sigt and lock in place via push pin on rsb and standard rear lock with recoil spring assembly.
Here's some pics.....
Photoshop concept drawing:
The cheap, dirty Bulgarian milled kit ( I got a Romanian front trunnion to go with it)
Some of the custom parts to go on the larger barrel...
Attachment 37200 Attachment 37202 Attachment 37203
The woods (yes, these are the natural colors of the wood)
i have been wanting to do a 10mm auto AK/krink style pistol for the longest time---
very nice bud... cant wait to see more.
Very nice! What's the ID of your rear sight block ?
Kragaxe just a thought from my experimenting....Have you considered using WSM brass? A little more volume, same case head & no frigging belt.
That looks nice, please keep us updated.
I looked at a lot of short mag brass. It has the same problem as a lot of others...availability and cost. Now I'm back to a buck or more per case....if I can find it. I looked for everything from 243 to 300 wsm and they are just too hard to find and cost way too much. I can get 500 of the 300 wm, cleaned and polished for $125. I can reform 450 and use the other 50 as-is for my win model 70.
Belted cases have good and bad points. I like using it to headspace off of. If I could have found a belted version of an 8mm mauser that would have been an ideal straight-walled 10mm supermag! The issue with belted mag cases are case forming and useful brass life. They take a little more care to get all you can get out of reloading without getting the dreaded bulge and case-head separation. For my model 70, I only neck size, so that doesn't seem to be an issue. It's a tight, accurate chamber and even with a sporter profile barrel I shoot single jagged holes out of 5-shot groups at 200 yards. I'm hoping that I can do a "match" chamber on this and still have reliable feeding. That will either extend brass life...or cause it to fail to cycle. :dunno: We'll see. There's going to be a lot of learning on this one.
A 1/2 a thousandth less than whatever the barrel was and pressed on. :) Hah! Offhand I don't know...I'll have to go measure it. I used some 4130 tubing, 0.065" wall and cut an inch section. I turned the inside to be about 0.001" less than the barrel, then polished the inside surface and welded the ring to the bottom of the chopped original RSB.
Originally Posted by dutigaf
Most pistols headpace off the case mouth. Unless you roto-rooter the chamber so oversize that there's no lip for the brass to stop against, it's no problem.
Originally Posted by kragaxe
Note the AK's bolt carrier stops solid against the pad on the left side of the trunnion, so the only "slide hammer" effect on the case is the weight of the bolt itself, as opposed to a complete slide assembly on, say, a 1911, which is supposed to have a gap between the barrel and slide, and headspaces on the brass case.
Heck, the Israeli Magal headspaced .30 Carbine on the case mouth, so there's an AK precedent!