The 7.62x39 AR...and the problems.

[DefendeR]

Hey friends:
I recently finished building a nice 7.62x39 rifle.
It is in the AR platform.I took it today to the range for a test drive,and found myself dealing with multiple FTF and FTEs.
I have known that there may be some problems with this particualar configuration,and in many cases the magazines are the main culprit.
I have 2 20 rd magazines,which I lightly dremel'd to keep the lip of them from preventing the round to load into the chamber.
I also polished the feed ramps.
At first,it shot fine save a few FTF,but then it got worse.
At times the bolt locked up and had to "mortar" it.
Any help will be appreciated.

 

[itchin]

sounds like your chamber is too tight for steel cased ammo. Pretty shitty because that's mostly all that's available in that caliber. 7.62x39 in an ar15 is a bad idea to begin with. If you need to shoot .30 cal out of an ar, go 300. In sorry you wasted your money. Maybe you can sell it to some sucker at the gun show.

 

[DefendeR]

Could be that.Maybe I'll run some brass ammo and see what happens.
If problem persists,then I'll just swap the barrel and convert it to 5.56.

 

[DefendeR]

On a side note,I got a couple of buddies that run that same config and theirs run fine,so let's see.
Thank you for the input.

 

[XinTX]

Most 7.62x39 ammo is steel cased and a bit on the nasty side. Not the best for a DI rifle. 300BLK seems to run okay, but it's mostly cut down 5.56 ammo with some fast burning powder.

 

[Saltyag2010]

I thought about building a 7.62x39 ar. It's all about using the right mags and upper parts. I didn't have confidence in myself to do it right.

 

[BIGPAPIGREG]

The 7.62x39 AR...and the problems....


because it's not an AK....

 

[rushthezeppelin]

Ya I don't understand this whole x39 AR craze. If I wanted to shoot that round I'd get an AK. If I want those ballistics in an AR I just whoop out the 300 blackout (which can also have similar ballistics to a .45 if I want it to).

 

[Younggun]

Yup, and buy up all that cheap $5/box 300BO ammo

 

[BIGPAPIGREG]

rushthezeppelin......what you said^^^

AK's have super loose tolerances, that's the way the platform was intentionally built, if you have ever seen a slow motion video of an AK rifle firing EVERYTHING flexes!!!! The barrel, receiver, rivets, etc ........it has to be loose so it can flex & distort, then come back into "shape" ....that's why they work so well, all the time

 

[rushthezeppelin]

Yup, and buy up all that cheap $5/box 300BO ammo

Never said it was cheap If you want cheap ammo get x39 and an AK and just shoot it.

 

[Younggun]

Cause AK has such great optics options, lol.

I have no interest in a X39 AR, but I can definitely see why people would want them and the advantages it would have over an AK or 300BO AR.

 

[itchin]

Cause AK has such great optics options, lol.

KalinkaOptics.com . There are other options like an eotech or a aimpoint. Anything you can put on an ar can be put on a ak.

 

[BIGPAPIGREG]

to the OP......I have heard & been told that the angle in which the 7.62X39 round has to be pushed up from the magazine into the chamber is quite a bit steeper when it is in the AR configuration vs the AK (more of a strait shot), which is the cause of a lot of feeding issues as well as chamber lock up issues for the AR configuration.....

 

[DefendeR]

to the OP......I have heard & been told that the angle in which the 7.62X39 round has to be pushed up from the magazine into the chamber is quite a bit steeper when it is in the AR configuration vs the AK (more of a strait shot), which is the cause of a lot of feeding issues as well as chamber lock up issues for the AR configuration.....

Thank you,I will take that into consideration.I'm still exploring my options.
I'm leaning towards swapping the barrel and bolt to a 5.56.
Not ready to abandon the 7.62,I just don't want to overreact.

 

[TheDan]

I have heard & been told that the angle in which the 7.62X39 round has to be pushed up from the magazine into the chamber is quite a bit steeper when it is in the AR configuration vs the AK

Yeah, that's definitely a huge part of it. 7.62x39 cases are tapered and have a hard time feeding from a strait magazine. A 7.62x39 "AR" would be a lot more reliable if the lower accepted standard curved AK mags.

 

[ed308]

Plus the bolts break. Won't own one.

 

[BIGPAPIGREG]

whuuuut???

 

[rushthezeppelin]

Yeah, that's definitely a huge part of it. 7.62x39 cases are tapered and have a hard time feeding from a strait magazine. A 7.62x39 "AR" would be a lot more reliable if the lower accepted standard curved AK mags.

They actually do make lowers that accept ak mags....they basically have no magwell. Of course that still doesn't fix the fact that most x39 bolts are prone to shearing lugs.

 

[BIGPAPIGREG]

They actually do make lowers that accept ak mags....they basically have no magwell. Of course that still doesn't fix the fact that most x39 bolts are prone to shearing lugs.

that is happening in the AR configuration?