Mags not fully seating

[Diesel1966]

Hi all.
I bought a S&W M&P AR15 Sport. It shoots very well is accurate enough, however I noticed the mags don't lock into place easily I have to hit them firmly for the catch to engage. I'm using the 30 round PMAG that came with, and 20 round Bushmaster mags. Has any else had this issue? Is it normal to have to use that much force? The mags feed fine, no ftf or fte. Any ideas or suggestions. Thanks. John

 

[Bradu]

Don't load the mags completely, load about 25 on the 30 round and about 17 on the 20 rounders and it will be fine.

 

[Diesel1966]

Tried that, what else could it be?

 

[bill_van]

DO the mags fall free easily? If not, check the mag catch adjustment.... Push mag release and look on other side of receiver. Rotate the catch 1 turn counter clockwise and re-test. If too tight, might cause a hanging on insertion and release. Don't go too far on this adjustment, there is a spring that will escape if you do. My experience is that looking at the mag release button, you should be about 1-2 threads below flush for proper function. The other issue was a few years back, S&W had receivers that were out of spec on the machining. They were to small internally and caused what you describe on PMags. They covered original owners, don't know about second owners. Im assuming you bought it second hand. Call them anyway they'll probably offer a solution. Good luck!

 

[Diesel1966]

Thanks bill van
I bought this rifle new 2 months ago. All the mags fall freely. No other issues. I'm not following what you are saying about adjusting the mag catch. If they're falling freely does this mean the adjustment is correct? John

 

[Smokerroller]

John, are you inserting the magazines with the bolt in the forward or rearward position? And can you insert an empty magazine and get it to catch and stay in there?

 

[Redmanss]

Thanks bill van
I bought this rifle new 2 months ago. All the mags fall freely. No other issues. I'm not following what you are saying about adjusting the mag catch. If they're falling freely does this mean the adjustment is correct? John

Take a small punch and depress the magazine release button until the catch extends past the receiver on the other side. Spin it one rotation counter clockwise to loosen it up a touch. Try your mags now with the bolt forward. Repeat if necessary, but make sure it's also still retaining the magazine as well. Falling freely along with seating properly means it's adjusted properly, not just one or the other.

There is absolutely no reason to load fewer rounds than capacity on a magazine. If they won't seat, then adjustments need to be made.

 

[JoshcBoucher]

Smack them HARD. That's what I do.. These Mags, these days, don't seem to work like the old mags. Just me.Josh.They "also" seem to malfunction more.Can we say that the "new manufacturing", isn't as good, as the old? YES, WE CAN!

 

[Diesel1966]

Thank you guys for responding. I am new to the AR platform and I'm enjoying it thus far.
So I tried adjusting the catch. I went in both directions and I finally settled on a spot that works great on the Pmags, without having to slap them in there. It works on the Bushmaster mags but I still need to slap these to get them to seat. This is with the bolt closed.... If I lock the bolt back, no problems. Now, if I insert an empty Bushmaster mag with the bolt closed no problem, locks in easily. What I also observed is on the side of the Pmags and the Bushmasters, the little cut out for the rifle catch are different sizes. The Pmag is a little wider than the Bushmasters. Also on the Pmags you cannot see the ammo brass through the catch hole. On the Bushmasters you can.. I'm going to try to uploads pics.

 

[Diesel1966]

Sorry, for some reason they're upside down...

 

[Smokerroller]

Without seeing how hard you have to slap the bushy mag it sounds like you might be functioning normally now. The magazine release button should have the little threaded part that sticks through the lower reciever, and through the release button, flush with the surface of the button your finger pushes. If its not flush but your weapon runs better like it is then I would leave it. Your resistance in seating the mag could come from the bolt catch not indexing on the bushy mag correctly but your adjustment of the mag release helped so it might be gtg.

 

[Diesel1966]

Thanks for everyone's help. Great group of guys. John