AR Issues

[17CulpeperMM76]

I'm having issues with my AR.
After a round is fired, the next round won't load. The bolt does not appear to be picking up the next round from the magazine correctly. It seems to miss the rim of the cartridge, and scrapes the top of it until it "tries" to load. It winds up pushing the round half way out of the mag, and jams.

Also, when I do fire the last round in a magazine, the bolt holds open, but only half way.

Hope I explained that well enough....I should have taken pics.

Any ideas?

Gunsmith recommendations in the Southern Chester Co area?

Thanks!

[TonyF]

That is a bolt-over-base jam.

Does this occur only with the same magazine or with different magazines as well?

Not stripping the next round out of the magazine would indicate short stroking due to a lack of gas pressure (from a gas leak).

Only locking the bolt "half way" indicates the bolt isn't really "locked" via the bolt stop. This is also a sign of low gas pressure but the BCG is obviously getting hung up on the magazine.

Let us know if the same problem occurs with different magazines. If it does then it's probably a gas leak. If it doesn't then it's probably isolated to that specific magazine.

[RXM]

One of two scenarios come to mind: bad magazine or short stroking due to gas or buffer weight.

Swap out mags. If it doesn't correct it then go on to diagnose the short stroking issues.

[17CulpeperMM76]

It has happened with all of the magazines that I have tried (5 different military mags, and two different brand new Magpul mags).

[RXM]

It has happened with all of the magazines that I have tried (5 different military mags, and two different brand new Magpul mags).

Next easy step would be to swap out the buffer. Do you know the weight of your buffer? Is it unmarked, marked with an "H" or any other markers?

BTW - check the gas key on your BCG to make sure it isn't loose.

[.45Kimber1911]

Sounds like it is short stroking. Clean and align your gas system and make sure your bolt carrier is lubed up and clean as well.

[Gun]

No given ammo, whether this problem just started, if the AR is new or used ....

Please, fill in the blanks.

[17CulpeperMM76]

Next easy step would be to swap out the buffer. Do you know the weight of your buffer? Is it unmarked, marked with an "H" or any other markers?

BTW - check the gas key on your BCG to make sure it isn't loose.

I'll have to check for the markings when I get home. It is an ATI Strikeforce set. I'm pretty sure it was labeled as the "civilian" buffer.

[17CulpeperMM76]

No given ammo, whether this problem just started, if the AR is new or used ....

Please, fill in the blanks.

Ammo is PMC 62 grain green tip.
Gun is pretty much new and has been doing it since the first time it was fired.

[RXM]

Is this a home build AR or off-the-shelf brand?