AK Sponsor
Posted: 4/11/2009 7:33:56 PM EDT
|
I've been dead set on a 7.62x25 AK for awhile . But after browsing around on weaponeer I feel a little more creative.
There seems to be alot more parts available still for the 7.62x39 rifles as compared to 5.45 and this led me to wonder about the possible .357 conversion given the proximity of the rim sizes. The only real potential I see for mags are the Desert Eagle variety. With the cartridge headspacing on the rim could I also shoot 38 specials?(m70 gasblock in whisper mode?) I am a big fan of the .357 and looking at Buffalo Bore loads in the Marlin 1894 puts it in the class with the 30/30 and 7.62x39. This would be tight with a Krink length gas system and a LaRue Irondot. |
|
I can see a few issues. (I have built gas operated 45 super and 45 winmag ak's, so I kinda have "been there")
1. apparently you want gas operated. So you will need a tighter seal on the gas piston. I used 4130 tubing from aircraftspruce (IIRC) they have the perfect size. Put your thumb over one end and pull the piston back and it "pops" with suction, yet moves smoothly. The factory tubes simply waste a lot of gas. if you find you are overgassing then drill vent holes a little closer to the gas block. 2. the eagle mags would likely be the only way to go with that rimmed cartridge. Mags are a lot harder to make then guns..... 3. the short length of the round and the rim will give you some problems. You have to get the nose of the bullet into the breach before the mag lips let it go. I tried several caliber conversions and this was one of the hardest problems. Some guns let the round "float" between the mag lips and the breach (being driven by the bolt feed lug) but you will be lucky to get it to work with only a few tries. Of course I have 300 grain weights at the front of the round , the front of the cartridge tries to resist movement while the light rear tries to swing around. It is not as pronounced with the 185 grain slugs so your even lighter round may not have this problem. 4. you will likely need to face the bolt a little to keep the bolt from hitting the breach before the rim hits the breach I look forward to seeing this if you ahead with it. You might want to go to the caliber conversion section of gunco.net for ideas. |
|
Using my '74 it looks like I can get the bullet almost in the bore before the feed lips let go. A little modding of the feed ramp will help take advantage of the single stack mag.
I had thought about doing a semi-bullpup to make it shorter and utilize the ergos and mag catch of the handgun but it just made it ugly and put my cheek on the dust cover + alter my sight options. So, I've settled on a conventional layout with the receiver shortened 1/2" in the front and 1/2" in the back + 1/2" off the back of the bolt carrier and bolt stem. I'm going to try to set the mag catch up ala AR so I can hit it with my trigger finger and let the mag drop free. |
|
Quoted:
I thought the desert used a semi double stack mag, alternating the base of the 357 rim to avoid hang ups? I don't know for sure , but the .44 DE I had for a few years appeared to be single stack. The sides of the mag were straight walled and only one cartridge appeared at the top. The rim of every loaded cartridge fell in front of the previously loaded cartridge. I believe my .44 held 8 rounds and the .357 holds 9. That kinda corresponds with a single stack .45 ACP(7?) The DE is a beast of metal and not much of that grip is dedicated to anything but the length of the cartridge. There may have been some "semi" to it , but I couldn't tell. |
| consider 9x23 win over .357 mag. Very similar rounds, except 9x23 is rimless and will work better in a magazine, anything that feeds 7.62x25mm should work i.e. ppsh-43 mags. you may need to cut away the bottom of the trunion to get the magazine close enough to the breech for positive controlled feeding. you could probably use a krinkov sized gas system, and a 5.45 bolt will work perfectly with the case head (same size as 9x19mm, 7.62x25mm). Only other problem is the scarcity/expense of 9x23. |
AK Sponsor