ar15 in 7.62x39

jar

I have heard they have problems feeding, any thoughts? is it magazine issues?

fordsix

they like good brass and not steel

yoshmyster

I was told that "The Mutant" was messy due to the piston action. Black face was the description after a day of shooting. As for feeding this was not the issue.

rufe-snow

You have to have a mag specifically made, for 7.62 X 39. I tried loading a standard 5.56 X 45 mag. You can only get, 3 in. A number of companies, make the special mags.

Supposedly, with the correct mags, BCG, barrel and adjustable gas block. It will function with 7.62 X 39.

dfletcher

quote:Originally posted by jar
I have heard they have problems feeding, any thoughts? is it magazine issues?


I've had one for a while and worked out a few kinks. CProducts mags work for me, not sure what name they're made under now. I also bought some "multi caliber" mags that handle 300 Blackout, 5.56, X39 & 6.8. Can't recall the name but they work as advertised for me.

I had an ignition problem, installed a heavier mainspring and that took care of it.

Mgderf

I built a Frankengun in 7.62x39 a couple of years ago.
I immediately had feed issues.
Resolved all my feed issues with CProucts mags specific to x39.

Mine will digest steel or brass cases equally well.

Mobuck

I've used a 7.62x39 AR for 10-12 years on an occasional basis. C-Products and some plastic ones(look like Thermold but unbranded) mags work well enough. I had a Colt(?) A2 configuration that didn't like bi-metal .311 bullets at all(think maybe it was actually a .308 bore) but a guy wanted it bad enough to swap me a brand new Olympic flattop version with a known to be .311 bore. Also have another still in the box flattop upper acquired on a "can't pass this up" sale.
GOOD magazines aren't that hard to find nor are they overly costly except for the previously mentioned "one size fits all" mags which cost around $40. For my use, this type is a "no go" as we may have AR's in 3 calibers in use at the same time. Having distinctly different magazines for the various rounds is a safety precaution.

nononsense

jar,

If you look at the comparison image below, you can understand the potential for feeding issues if the case is not taken into account.



The 7.62 has more taper in the case, it's slightly shorter and it's a larger diameter, obviously. These elements are taken into account when we use the stylized 'curved' magazines to hold these cartridges for proper feeding.



Note the more pronounced curve in the 7.62x39 mags as opposed to the 5.56x45 magazine in the comparison.

Another potential place for failure is when companies use the standard M4 feed ramp in the barrel extension which will cause no end to headaches when trying to diagnose the problem. This has mostly been corrected over time but some of the older AR's might exhibit the problem.

In conjunction with the feed ramp, there should be a slight taper at the rear of the chamber on the breech end of the barrel. This will be both larger in diameter as well as a slightly different taper than the 5.56 has to provide the perfect feeding from the magazines.

Feeding issues can often stem from the gas block set up also. It affects the BCG timing. The exit hole is the wrong size or the gas block itself is not designed for the amount of gas and pressure curve of the 7.62x39 cartridge. Placement on the barrel will have an effect as well.

When all of these little problems are addressed properly, feeding is not an issue.

Best.

carbine100

Have had no problems at all. Have only used brass ammo (new and reloads) and cartridge specific mags.

jar

thanks guys all good and usable info. thats why I hang out here.

booger

This mongrel never stops. Anderson lower & upper? It was sitting at a gunshow table lost in the tacticool department. I bought it up, removed about half of what you see there, and have been relentlessly blasting away. Never cleaned either, nary a problemm with all kinds of ammo. Just shooting and smiling.[:D]