Magazine won't lock into AR-15

[flashgor_99]

Tried posting earlier, but apparently didn't work. Forgive me if this is a double post.
Recently built my 1st AR-15. Worked great! After a couple hundred rounds, now sometimes the magazine won't lock into place. Push it in, drops to the ground. Before I start taking everything apart, was wondering if anyone has any tips on how to adjust it or just what the problem is? Thinking it could be just as simple as my buying cheap-assed magazines and my (spent more than the wife knows) gun refuses to associate with it.
Thanks

 

[Brains]

Look for the simplest things first - mag release button stuck?

 

[outdare]

Guess check and see if you put the correct spring in and adjust the tension.

Sent from my SM-N920V using Tapatalk

 

[boomgoesthedynamite]

Second on the mag release button being too set incorrectly.

Sent from my Pixel XL using Tapatalk

 

[vmax]

Try a couple of different mags

 

[Dawico]

Think these guys have it covered.

Either the release button isn't set right or the magazines are bad.

Simple fixes for either.

 

[Vec]

what brand lower, what brand lower parts kit. what brand magazine?

 

[Mikewood]

I would remove the magazine button and parts. Then try to seat a mag and see it if come up to the window in the lower. If it does wth a tiny bit of gap before it hits the bolt you are good. Just reinstall the mag release and be sure it's all the way in as far as you can turn it. If not then try another mag. Magpul etc. if it still won't you may have to replace the lower. The mag well spring could also be broken.

Little aftermarket parts kits sometimes come with defective parts that break within a couple hundred rounds of being installed.


Sent from my iPhone using Tapatalk Pro

 

[HKShooter65]

3 parts involved:

........................

1. Mag.
Easy to try another.

2. Receiver.
Worked for hundreds of rounds, unlikely the problem.

3. Mag lock/button/spring assembly.
The likely culprit, though if it's binding or improperly installed I'd think it would be an obvious culprit.

........................

You've figured it out by now, I'm suspecting, if you are skilled enough to have assembled it originally.

Let us know.

 

[hellishhorses]

A fully topped off mag can put pressure on the bottom of the bolt and not allow the mag to be fully inserted.

1. Lock the bolt to the rear and insert the mag
2. Try inserting an empty mag
3. Break the rifle open and insert a mag to see why it's not locking into place

 

[Ozzman]

No one has asked the question if your lower is made from aluminum or polymer??

FYI
I owned a polymer ATI lower a few years ago and quickly found out that Pmags (Gen 2 & 3) would not fit right in the magwell. They exhibited the same symptoms you describe with magazines would not lock into place.

 

[Chucky C]

I have the same issue and 4 things that are mentioned here has happened with my Magazines
1.- only works with empty mags
2.- my lower is made out of polymeter
3.- with full mag the bullets put pressure on the bolt so I have to give it a hard knock on The bottom of the magazine
4.- It works Fine when I pull the bolt all the way back without issues

the question is this how can I do to make it work normally without having to go through these steps

 

[Pops1955]

Load one less round.

 

[ZX9RCAM]

I have the same issue and 4 things that are mentioned here has happened with my Magazines
1.- only works with empty mags
2.- my lower is made out of polymeter
3.- with full mag the bullets put pressure on the bolt so I have to give it a hard knock on The bottom of the magazine
4.- It works Fine when I pull the bolt all the way back without issues

the question is this how can I do to make it work normally without having to go through these steps

Welcome to the Forum!

 

[SQLGeek]

Load one less round.

Yep. Or try a different brand of magazine.

Depending on tolerances, full magazines can be very difficult to seat on a closed bolt.

 

[baboon]

Underload your magazines 2-3 rounds.

 

[Ozzman]

Load one less round.

Yep. Or try a different brand of magazine.

Underload your magazines 2-3 rounds.

Yes, yes and YES!
All three of these are possible solutions.

The only problem is... a proper AR 15 must be able to use ALL types of magazines whether fully loaded or not. My recommendation, pick up a $50 aluminum receiver (Anderson, PSA, Primary Arms, etc) and remove/toss that polymer lower in the parts bin. I am 100% sure that will solve your problem.

Keep the polymer lower for future .22 lr rifle builds.