Mags won't seat m&p9 fs

[bigm1717]

Just got back from the range. I only brought one magazine with me, (a 10 round one), and when the magazine is at full capacity and the slide is closed the magazine won't seat. Works fine with 9 rounds, or 10 with the slide locked back. Is this normal? P.s. Like always the gun fired flawlessly!

 

[lhump1961]

Is it a new mag? If so it will get better with use but many of the fantastic plastic guns (all manufacturers) are made to a very tight tolerance with full mags...I assume to make the dimensions as small as possible. My M&Pc's were very tight at first but got much better quite quickly. Leave the mags fully loaded for a week or two and see if they don't get better.

Although my mags were tight at first I could still seat them with a good whack! I can't remember which Glock model it was but Hickok 45 doesn't put the last round in the mag for that very reason.

Post with your results.

 

[bigm1717]

It's the mag I most commonly use. I have left it fully loaded for a week at a time a couple of times. I can load it up with just my hands (it is a little difficult, but not nearly as difficult as when it was new).

 

[blujax01]

Spank her like she's been naughty!

 

[Bkreutz]

Don't know about the 10 round mags in a FS, but I had the same problem with the 12th round in my 9c. I took the 12 rounder and a 17 rounder apart, what I found was that the spring was the identical length in both of them (I did this after sanding 3/16' off the follower legs with no change). I clipped one loop off the spring and now loading a full mag with a closed slide is no problem. All I can surmise was that the spring in the compact was "spring bound". When inserting mag the top round gets pushed down into the mag. I never had the problem with the 17 round mags. I realize that the 10 round mags are something I have no experience with (never even seen one "in the flesh"), but this is a thought. Who knows, maybe Smith only has one length of a spring for a double stack mag.

 

[K_Mac]

If it continually gives you problems after what you feel is a good amount of time for it to break in go ahead and start trimming the spring. If you start having feeding issues replace the spring and start over.

Eventually you may have to cut your losses and trash the mag. I've only had to do this a couple of times with metal AR mags, no matter what I did the mags would not feed reliably. If you don't want to trash it then mark it clearly so you don't use it for carry or self defense.

 

[Jdugan4859]

They use the same spring in the 10, 12, and 17 mags all have the same spring in them, I just took a couple loops of the 10 and 12 springs and they work fine.

 

[shawn mccarver]

Just got back from the range. I only brought one magazine with me, (a 10 round one), and when the magazine is at full capacity and the slide is closed the magazine won't seat. Works fine with 9 rounds, or 10 with the slide locked back. Is this normal? P.s. Like always the gun fired flawlessly!

Normal. Tight tolerances so that you cannot shove an 11th round in the magazine as that would make it illegal.

Just load one round down.

 

[bigm1717]

I really wish I had brought another mag with me, just for clarity of removing the firearm from the possibilities

 

[Nick54]

Spank her like she's been naughty!

All she needs is a good hard whack with the heel of your hand, she'll loosen up eventually.

 

[Hillbilly77]

Just got back from the range. I only brought one magazine with me, (a 10 round one), and when the magazine is at full capacity and the slide is closed the magazine won't seat. Works fine with 9 rounds, or 10 with the slide locked back. Is this normal? P.s. Like always the gun fired flawlessly!

That is a common problem with the 10-round 9MM magazines.
There is also an easy solution.

You just need to trim the plastic followers in the mags.
The 9MM mags are so tight that it's hard to get the 10th round in, then it's hard to seat the mag as you've noticed.

Just trim roughly 3/16" off the legs of the followers - problem solved. This has no effect on the spring tension so feed won't be affected.

As shown - the trimmed follower on the left, the new one on the right:

 

[SW-Dyne]

Agreed, trim a little off the legs of the followers and 10 will seat fine. I also removed a couple loops while I was at it. I can now hand load 10 rounds in 3 relatively new mags. I've got about 100 rnds ea. and no issue so far.

 

[bigm1717]

going to try the trimming tonight. i'll let you guys know how it goes. thanks for the input

 

[scattershot]

I think that's normal, all my mags do it. Before you go trimming the springs, just try giving it a good smack to seat it, or load the mag with the slide back. Trimming springs is generally a bad idea, IMO.