Can't get last round in magazine

[daddyo]

Last week I went to the range to get some trigger time with my M&P45c and 9c just to make sure that everything works the way it's supposed to. When I got home, I loaded up the 45 with SD ammo, but I couldn't top two of the mags off. They hold 8 rounds, but I simply couldn't get that last one in. They weren't a problem before I went to the range, and I had no problem getting them loaded to capacity while I was shooting. The other two 45 mags were no problem.

Just wondering what the problem might be. Edited December 9, 2012 by DaddyO

[Defender]

I have had the same problem with some mags. ANd with some the mag doesnt rattle until I get the last round in, then it will rattle...

[VERO1]

I had a Keltec that would happen to. I think it was the way the spring would compress in the magazine. Occasionally it would bind or kink a little when compressing. I took the magazine apart and cleaned it and lightly lubed it even though it looked fine. Worked well after that.

[mikegideon]

I have a bunch of different mags that are cranky with the last round. Haven't tried to analyze it. I just use an Uplula.

[daddyo]

The problem is, when I am able to cram the last round in the mag, then I can't insert it into the magwell. Seems like it would have to be the spring.

[mikegideon]

[quote name='DaddyO' timestamp='1355064479' post='857191']
The problem is, when I am able to cram the last round in the mag, then I can't insert it into the magwell. Seems like it would have to be the spring.
[/quote]

I don't know. I don't have any M&P's right now, but run into it with my Glocks and 1911's. I always had that problem with my Model 59 Smith. I always just loaded them 1 short (13 rounds). I know you probably don't wanna do that, especially with a compact. You can try swapping springs and see if the problem moves with the spring. As I recall, the M&P mags come apart pretty easily. Glock mags are a pain in the butt, so I just take what I get with them. Edited December 9, 2012 by mikegideon

[Djay3]

That is odd. You might try loading the problem ones as full as you can get them and let them sit a couple of days to "break in the springs a bit more" then retry.