I posted this in the Build Forum, and someone suggested that I try my question here.....


I'm in the middle of my first build,and I'm getting to the point of making a final decision on the length of barrel and caliber. I really like the looks of a 7.5", but I am aware of the reports of less than stellar reliability and ballistics. Complicating the decision is my fondness for the 7.62x39 cartridge. Is it possible to build a 7.5" AR Pistol in 7.62x39 and have it function reliably without beating itself to death? Are there any suggestions on how to accomplish this, or anyone want to talk me out of it completely? By the way, this pistol will be SBR'ed once it's build is finalized (and BATFe has their 8 months of fun)..

Thanks in advance for any help that you guys can offer to a first time builder.

I've built a 7.62x39 pistol and had no problems with it at all.  I fired approximately 2000 rounds through it with only a few FTF...I'd say about 5/10 times.  I was using the crappiest ammo I could find and I never cleaned the gun at all. In my experience (Limited to the very few rounds I shout through the gun) you shouldn't have any issues at all.  My only hang up I guess with the gun was that I hated the way the 7.62 mag looked when inserted in the gun.  I like the more classis lines of the original 5.56 mag which is why I really like the 300 blackout.

I'm building a 7.5" 7.62x39 pistol.  I have most the parts except the bolt  I originally planned on using AR15performance's 7.62x39 super bolt, but they discontinued them.  I will probably use a ARP 264 bolt with a M1S extended firing pin.  I expect the biggest reliability issue to be finding good magazines.  I back ordered 10 about five months ago, but they still haven't showed up.  IME with other 7.62x39 guns they often needed the bolt tail shortened for reliable primer ignition.  Using the M1S firing pin should solve this issue for me.  I'll probably drop in an extra power hammer spring as well, just to ensure I don't have any problems.



As far as beating the gun up, I don't see it as a big issue.  I will probably start with an H1 buffer and if it seems to be cycling too quickly I'll move to an H2 or H3 buffer.  If I could find the bolt I want I might be of more help.

       
 

Here's mine,

May need alittle fine tuning, like o-ring around the extractor, enhanced firing pin, if you break a 7.62 extractor a 5.56 works just as good, H2 buffer, I even widen the M4 feed ramps alittle and runs like a top shooting nothing but Tula steel. It's my favorite gun to shoot at 50 feet or less in the pistol pit.

I've been thinking of going back to iron sights cause the red dots take a good beating after 1000 rounds.



Can you tell which one is shooting 5.56 or 7.62

Thanks for the support guys. I have spoken with some AR "elites" and most of them just tried to make me feel dumb for wanting to do something a little different.i appreciate the tips as well. Its good to know that what I would like to do isnt impossible.

What magazine is that and how well does it function? Any tips to offer?

It's a AR Stoner mag I got from Midway last year. Works great after it's broken in, at first I just loaded 20 rounds and after 500 rounds later I can load 30 rounds alot easier now.

Also check the mag spring cause on one of mine I had to rotated it 180 degrees so it would push the front of the follower up.

They are fun to shoot up close and destorying softballs at 50 feet is awesome

If you like alot of bang and flash your going to love it, plus you get alot of folks that just look at you with their mouths open then say what the heck are you shooting

I'll check it out..thanks for the tip.