AR Magazines Not Seating

[R_Shackleford]

I just put together my first personally owned AR-15. Up until now I have mostly shot AKs. I haven't even taken it out yet but I tried loading some magazines into it and I have been having problems getting loaded mags to seat in the magazine well with the bolt forward.

I have tried most of the conventional wisdom. I tried loosening the magazine catch and only loading 28 rounds. No dice. Empty mags seat just fine. I tried putting in one round at a time to see how many I could fit before it doesn't seat. The magazine doesn't seat at 3 rounds. I have tried Magpul and USGI mags (new magazines). I can get it seated if I slap it like a red headed step child. If it makes a difference, I assembled the lower from a stripped receiver. The upper was factory assembled.

Its not an issue when shooting for fun but if I get into a situation where I need to do a tactical reload under stress, this is going to be a problem.

What gives? When I was in LE, I carried an AR in my patrol car and I don't remember ever having this problem. Is my bolt out of spec? Do I just need to break the mags in?

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[Sniper03]

Shack,

You have already used the various Magazines to determined it is not the Mags.
Since it is almost impossible to diagnose this issue even over the phone. What brand of Lower Receiver do you have. I would suggest you try the following.
Find a friend or someone that has a good quality AR-15. Try his complete Lower with your Complete Upper. And also try his complete Upper on your Lower. Also try your Magazines in his Lower. At least by doing this you will be able to locate where the problem is. In the Upper or the Lower, other than just guessing and being confused about where the issue is. I use this technique all the time if I can not isolate it. If there is a sever dimensional problem this will point you in the right direction. Let us know.

Sniper03

 

[titsonritz]

I suspect you mag catch, spring or lower is out of spec.

 

[R_Shackleford]

Lower receiver is from Spike's Tactical

 

[titsonritz]

What about LPK?

 

[Stomper]

If the bolt drags on they feed lips of an empty magazine, your lower or upper is out of spec.

Try your upper on a known good lower and see if that persists, then do the math from there.

 

[R_Shackleford]

Most of the rest of the gun is Rock River Arms except for the buffer tube and charging handle are BCM and the Trigger is Geissele.

 

[R_Shackleford]

bolt doesn't seem to be dragging on the feed lips

 

[titsonritz]

Do you have another AR available to you that is a confirmed shooter?

 

[R_Shackleford]

not at the moment. I have some other stripped lowers but I don't have the parts to build them right now. too many guns I want to buy and I have about 4 simultaneous gun projects going on which get completed as I have disposable money. I know. I have a problem. I can't find a gun addiction center.

 

[HB of CJ]

Easy to conduct some quick field function tests. Grab the lower and put your middle finger up into the mag well. Feel for the mag catch tit. It should protrude some into the mag well. Now feel for the mag release tit arm. It also MUST protrude slightly into the mag well. Flush is not good.

Try adjusting the spring until the screw just rests below flush with the mag release button. Then try slamming home some empty mags with a firm fast smack from your palm heel. The empty mag should click home. Then try with a fully loaded mag. Safety first. Slam it home hard.

It should also click into place. There may be resistance from the round stack. This is normal if only a slight amount. If the loaded mag does not click in, then open the rifle. Gently click in an empty mag. Then close the rifle. The rifle should close easily with no felt resistance.

Then click in a fully loaded mag and gently close the top and lower receivers together. There should be some felt resistance but not too much. You should be able to close the halves with a loaded mag clicked in. If you can not, then there is some dimensional problem with one or both halves.

Edited extra: The BCG is closed doing this. NOT locked open.

Hope this helps. Edit: Forget to say try many different types of mags. Data base needed.

Hundreds of builds. EQUAL PARAGRAPH LENGTH IS FUTILE. I HAVE SURRENDERED.

 

[etrain16]

I had a similar thing happen on one of my builds. The consensus, after checking numerous things, was that the lower itself (Anderson), was out of spec and no amount of adjustment was going to fix it. Hadn't had any problems with out of spec lowers, including Anderson, before that.

 

[R_Shackleford]

Okay, I installed the mag catch on one of my stripped lowers and put the upper on it. Same problem. Unless both lowers are out of spec (unlikely), I'm thinking it has to be either the mag catch or the upper.

 

[JRuby]

I have problem seating loaded P-mags on all three of my AR's with the bolt forward. I thought this was normal behavior. I have a riger ar556 a ruger sr556 and a Franken gun with a sig receiver and Anderson lower. Am I wrong on this?

 

[Kruel J]

Try seating them with the upper removed.

 

[808hondacrguy]

Or with the bolt in the charged position.

 

[Kruel J]

Or with the bolt in the charged position.

Yup!

 

[R_Shackleford]

Seats fine with the upper off. Its gotta be the upper.

 

[R_Shackleford]

I have problem seating loaded P-mags on all three of my AR's with the bolt forward. I thought this was normal behavior. I have a riger ar556 a ruger sr556 and a Franken gun with a sig receiver and Anderson lower. Am I wrong on this?

Every AR that I have shot wasn't this hard to load, especially with only putting 28 rounds in the mag. Plus, doing a tactical reload like this would be damn near impossible if I am getting shot at.

 

[rick benjamin]

Remove BCG and charging handle, assemble upper and lower.
Does mag seat?