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View Full Version : Issue with new AR, any thoughts?


MoabFJ
03-04-2010, 9:23 AM
This is my first AR, so I am new to the EBR thing, if not shooting in general.

The rifle is a new factory built CMMG carbine, and the mags are a mix of Sabre and Magpul 10/20 mags, all plastic.

The first time I took it out to shoot at Chabot and it was perfect.
It ate several different brands of factory ammo, and was reasonably accurate, in short, everything I was looking for.

The second time I went out I started having problems. After a few shots, the magazine fell out. Then I noticed how hard it was to get the magazine to seat.

I spoke with the dealer and they have mentioned the possibility of plastic mags swelling, or having a poor fit due to the factory coating on the rifle.
I have looked at it closely, and really don't think this is the problem.

If anyone needs a specific picture to help clear things up, I will post it.
Does this sound familiar to anyone?

Thanks, any help is appreciated.

Arteel
03-04-2010, 9:26 AM
Are you trying to load a full mag in your rifle with a closed bolt?

MoabFJ
03-04-2010, 9:30 AM
Well.. yeah. In every rifle and pistol I have ever owned.

Shoot till the mag is empty, chamber clear, bolt closed.
Insert fresh mag, cycle bolt, repeat..

This is wrong?

DDRH
03-04-2010, 9:34 AM
Well.. yeah. In every rifle and pistol I have ever owned.

Shoot till the mag is empty, chamber clear, bolt closed.
Insert fresh mag, cycle bolt, repeat..

This is wrong?

nothing wrong with it...but with 10/20 and 10/30's some may not have enough room for play, and maybe a bit tough to load the mag in the magwell. in this case, the mag may fall out if you don't give it a good slap to make sure it's in.

some with 10/20 10/30 mags usually load 9 rnds if they have issues loading 10.

i have no issues with any of my PMAGs. 10/20 10/30 30's. try some regular milspec mags and see what happens.

MrNiceGuy
03-04-2010, 9:36 AM
Almost all AR shooters only load one minus the max capacity of the mag (even on non modified 10 or 30 rounders) when loading from a closed bolt, or else you have to jam the mag in HARD to get it to seat properly without falling out.
Don't have a technical explanation for you, that's just the way it is.

Or, if you must load a mag to max capacity, then you're only option is to load the max from an open bolt and then close the bolt.

technique
03-04-2010, 9:37 AM
nothing wrong with it...but with 10/20 and 10/30's some may not have enough room for play, and maybe a bit tough to load the mag in the magwell. in this case, the mag may fall out if you don't give it a good slap to make sure it's in.

some with 10/20 10/30 mags usually load 9 rnds if they have issues loading 10.

i have no issues with any of my PMAGs. 10/20 10/30 30's. try some regular milspec mags and see what happens.


^^pretty much this above^^

It's because you have "limited mags". You didn't give it a good enough slap when inserting it you should also give it a good tug to check.

You should with normal mags or factory 10rnd mags, be able to load on a closed bolt....that's what a Tac reload is. (dropping a half empty mag to insert a fresh one)

dieselpower
03-04-2010, 9:51 AM
Its not just 10/XX mags either. I own several 10rd mags that need to be slammed in if loaded to capacity.

Some people are a little taken back with the amount of force it takes to seat a full mag on a closed bolt.

MoabFJ
03-04-2010, 9:57 AM
While I was looking things over last night, I noticed that one of the top rounds in the magazine (had been cycled) had badly dented brass. I assume that is from forcing the full mag to seat.

Good advice. I will load 8 and 9 and see if that fixes things.

supermario
03-04-2010, 9:58 AM
This is probably not it but I remember my Sig 556 would have problems with the mag falling out and not seating etc. It turned out it was my Bullet button would get stuck in or half way in and not allow the mag to seat or it would just fall out. I would use a tool to monkey with the BB and then the BB would pop back up and no more issues. This still happens once in a while but it was always my BB. I been meaning to change to the latest raddlock or just get a new BB.

Army
03-04-2010, 10:01 AM
Leave the bolt open after the last shot, then insert the mag.

Full magazines ram the top cartridge against a closed bolt, more force is needed to compress that round back down into the magazine so the unit can be inserted far enough for the magazine catch to seat.

Leaving the bolt open negates all of this, since the top round touches nothing.

OffGrid
03-04-2010, 10:02 AM
Moab, I have made many 10/20 and 10/30 mags for myself and some friends and we run into the same issue.

With at least 6 different kinds of magazines, a whole bunch of different ammo manufacturers and probably about 20 different AR configurations and most of them will not lock in with a full 10 on a closed bolt. You can slam them in there but it takes a pretty good whack, more than I want to do.

I make the magazine blocks out of aluminum tubing so it is very easy to play with different lengths but to get the magazine to easily lock on a closed bolt it just leaves too much of a chance to cram an 11th round in there. Even more so when the feed lips start to get weak or bent.

So the round about answer you probably already got in the time it took me to type this. Just load up 9 rounds and call it good.

Robert

MoabFJ
03-04-2010, 10:55 AM
Done and done.

Thanks all!

BRANDON7766
03-04-2010, 11:06 AM
I had the same issue...it actually resulted in some feeding issues...now I load 9 and no issues AT ALL.

DDRH
03-04-2010, 11:44 AM
The second time I went out I started having problems. After a few shots, the magazine fell out. Then I noticed how hard it was to get the magazine to seat.

I spoke with the dealer and they have mentioned the possibility of plastic mags swelling, or having a poor fit due to the factory coating on the rifle.
I have looked at it closely, and really don't think this is the problem.

If anyone needs a specific picture to help clear things up, I will post it.
Does this sound familiar to anyone?

Thanks, any help is appreciated.

This is probably not it but I remember my Sig 556 would have problems with the mag falling out and not seating etc. It turned out it was my Bullet button would get stuck in or half way in and not allow the mag to seat or it would just fall out. I would use a tool to monkey with the BB and then the BB would pop back up and no more issues. This still happens once in a while but it was always my BB. I been meaning to change to the latest raddlock or just get a new BB.


this may be something to look at too, if you're saying you shot a few rounds before the mag fell out?

was the mag resting on something (holding the mag in the mag well?)?

Josh3239
03-04-2010, 12:17 PM
Why are you guys inserting mags on closed bolts? After the last shot the bolt locks open and you should leave it that way. When I arrive at the shooting range and take the rifle out of my case I always lock the bolt open for that reason plus it makes the rifle "safe".

Also, when you insert a mag the best way to make sure it is locked in is to use push/pull. If it is locked in you won't be able to pull it out.

Andrew17019
03-04-2010, 12:22 PM
If you're shooting with an AR, you may want to check the magazine release button as well to ensure that it is not too tight or loose. If it's too tight it can potentially hold the magazine in the well without actually clicking in place until you fire a few shots...then it will loosen out. Adjustment is easy, just overdepress the magazine release button and turn your magazine tab to tighten or loosen.