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...
SS13.jpg SS33.jpg SS24.jpg
The woods (yes, these are the natural colors of the wood)