Magazine Issue

bobboodis45 · #1 01-14-2015, 11:01 PM

Hello all,
So the other day i went to the range and shot a few rounds with my M&P15 sport. And what was odd was when I went to insert the magazine it wouldn't lock in the upper. I have two gen 2 pmags and it happened with both of them. What i found odd was when i took out a round to make it 29 rounds rather then 30 it locked. So I figured that was the problem and I just can't have a full mag. But later in my session I only loaded 15 rounds, and it didn't lock. Has anyone else had this problem?? Thanks guys

gunny4053 · #2 01-14-2015, 11:20 PM

Definitely not what you'd normally expect from the Sport or Pmags. Were you loading these with the bolt open or closed?

bobboodis45 · #3 01-14-2015, 11:25 PM

I've usually never had a problem with either of them. Still love and don't regret getting my sport. And if I remember correctly it was closed. Although it could have been open.

Tbat · #4 01-14-2015, 11:50 PM

Are the PMags tight in the magwell, i.e., are they hard to insert and remove? I have not had that problem with my Smith & Wesson lowers, but I have seen two different DPMS lowers that some first or second generation PMags would get stuck before locking in and while other newer generation PMags would work just fine.

If you are getting your mags fully inserted and they are not lociking in, you might also try adjusting the mag catch by turing it a couple of turns. Take the upper off and insert a mag and look down at the mag catch and see what is happening.

JaPes · #5 01-15-2015, 12:24 AM

The follower in a fully loaded mag doesn't have much room to move, especially a mag with a new spring. With the bolt closed, the top round in the mag pushes against the bottom of the bolt. Since there's no room for it to compress, the notch in the mag won't reach the mag catch.

1. Try vigorously inserting the mag. Push it into the magwell and give it a bump.

2. With the BCG locked back, insert the fully loaded mag. Drop the BCG.

gunny4053 · #6 01-15-2015, 12:49 AM

Quote:

Originally Posted by JaPes

The follower in a fully loaded mag doesn't have much room to move, especially a mag with a new spring. With the bolt closed, the top round in the mag pushes against the bottom of the bolt. Since there's no room for it to compress, the notch in the mag won't reach the mag catch.

1. Try vigorously inserting the mag. Push it into the magwell and give it a bump.

2. With the BCG locked back, insert the fully loaded mag. Drop the BCG.

Good advice. Don't be afraid to slap the tar out of the bottom of the mag. If there is a real issue, dropping the bolt on a full mag from the open bolt position will make it show up quickly. Good Luck and good shooting.