Mag fit is too tight - Solved!!

Ganderite

Ganderite

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I have a pair of new Ar15s. Both of them require a very hard slap to seat the mag - even with the bolt locked back. This is with both C mags and P mags.

What should it do so that the mag will click locked with only light pressure?

I was considering sanding the the top surface of the lock. I bet it would work better if I could take about 1 mm off it.
 
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How are they riveted? I know with mine I had to file the rivet a bit to get it to be able to insert and extract the magazine easily, and even then the rivets still rub against the magwell. As well I had to lightly file down the pmag itself

Before you alter the rifle, I recommend seeing if you can try multiple other magazines.
 
Could the mag release slot be placed too high?. What is the distance between the top of the lower reciever and the top of the mag release slot?. on my norc reciever the distance is .680". slot width is .255". good luck.
 
I bought a Stag 3G several months ago which had a tight fit with new PMags.
A few quick passes with a file took care of that.
The metal 5 rounder that came with the rifle however will not drop free from any of my rifles.

Also if the new PMag is a Gen 3 you may need to trim the top of the tabs slightly to get them to fit tight mag wells.
 
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The C and P mags work fine in other rifles, so not a mag issue. Not a rivet issue, either, since the mags use internal blocks.

I think I will buy the mag lock part and experiment shaving a bit off the top. With a spare part in hand I won't risk knocking the rifle out of commission.

"A few quick passes with a file took care of that."

What did you file? The top of the mag? When a mag has to be hit hard to get it to seat, what part of the mag is bottoming out in the action?
 
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Do you still need to slap the mag hard when it only has 4rnds in it? Oops, forgot you mentioned inserting it with the bolt locked back. Maybe remove the mag catch and file down the top of it.

thump_rrr said:
The metal 5 rounder that came with the rifle however will not drop free from any of my rifles.
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I had the same problem with a couple LAR15 mags I bought off Questar. I had to put a rubber mallet to them to get them to drop free. The 10rnd XCR Pistol mags from Wolverine are made of steel and drop free.
 
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I'm assuming these are the two NEA guns you just bought? You should put this issue in your review.

I have seen cases that when the mag catch is not screwed in all the way, the mag will sit low and the gun will not shed rounds properly but I can't imagine having it screwed in too far would cause the problems you are having. Just in case, make sure the screw on the mag release is flush with the face of the button.

Before you modify the mag release, check to make sure the upper is not preventing the mag from fully seating.

If you have to remove .04" from the mag catch to get the mag to seat properly then your lowers (or possibly uppers)are out of spec and you should contact the manufacturer for replacements.




And before anyone jumps on my case; my advice would be the same regardless of whether these guns were NEA, Stag, Colt, or KAC
 
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I just played with the two problem rifles and a Norc. With the Norc the mags slip in and click locked. It feels as if the mag would go slightly farther if the latch did not stop it.

New rifle #1 the mag slides in and locks at exactly the same point the mag bottoms out. If there are rounds in the mag and bolt closed, it takes a slap to seat it.

new rifle #2 the mag slides in and needs a light tap to get it to latch. If there are rounds in it, it takes a stronger tap. In the shop it does not seem much of an issue. On the range it was an issue.

When the mag bottoms out, what part of the mag is hitting the lower? maybe a 1 mm shave with a file would solve the issue.
 
The mag doesn't bottom out on the lower (in theory). It will bottom out in the upper. And again, you shouldn't have to be 'fitting' anything on a new gun. Let alone two new guns from the same company.
 
Swap the upper on the NEA to the lower on the Nork and the upper of the Nork to the lower on the NEA and then try and insert the mag. That should give you an idea as to where the problem lies.
 
"you shouldn't have to be 'fitting' anything on a new gun."

good theory, but something needs tweaking - and re-locating the position of the mag release about 1 mm is not an option.

I can see that the shoulder of the mag bottoms on the bottom of the upper. With P mags it will be easy to shave the plastic 1 mm and let the mag go in a bit farther.

But this is the kind of QC issue that can get someone killed. mags should not fall out.
 
But this is the kind of QC issue that can get someone killed. mags should not fall out.
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Which is exactly why you should contact the manufacturer and get the out of spec parts replaced

I can see that the shoulder of the mag bottoms on the bottom of the upper. With P mags it will be easy to shave the plastic 1 mm and let the mag go in a bit farther.
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Be careful. I don't have a pmag in front of me but .04" might be enough to compromise the integrity of the feed lips
 
How cold was it when you tried the mags last?. I remember some of the old thermold mags didn't like to seat in my c-7 when it was cold out. I broke a few of them trying to "tap them in".
 
xenasdad said:
How cold was it when you tried the mags last?. I remember some of the old thermold mags didn't like to seat in my c-7 when it was cold out. I broke a few of them trying to "tap them in".
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That doesn't really explain the other, non polymer/plastic, mag having the exact same issue.
 
Ganderite said:
"you shouldn't have to be 'fitting' anything on a new gun."

good theory, but something needs tweaking - and re-locating the position of the mag release about 1 mm is not an option.

I can see that the shoulder of the mag bottoms on the bottom of the upper. With P mags it will be easy to shave the plastic 1 mm and let the mag go in a bit farther.

But this is the kind of QC issue that can get someone killed. mags should not fall out.
Click to expand...

So the mag release is out of position by .040?. Thats an awfull lot.
 
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