9mm M&P, M&P Compact and Sigma mags...

[mr.72]

ok ladies and gentlemen...

First the question and then the background...

will a full size M&P 9mm magazine fit and function in a M&P Compact 9mm?

and then (likely in your opinion, if you happen to have seen them) will a M&P magazine, apart from base plate interference, fit and function in a Sigma?

The reason I ask is because I really dig my Sigma and don't want to sell it or replace it with something else. However I might consider shortening the grip to make it easier to conceal if there was a readily-available magazine that would fit in and work.

Just looking at pictures it appears that a M&P Compact magazine might do the deed... looking at a picture of the two magazines (Sigma and M&P-C) overlaid it looks like the mag catch is in the right spot (might require a little reshaping) and the only other difference would be at the end of the grip:

thoughts?

 

[Butter]

Probably will. But to be honest, I am not a fan of using full sized mags (mags meant exclusively for the full sized versions compared to their smaller siblings) in compact and subcompact models even if they fit. The reason:

Have you ever tried to do a quick tactical reload drill or a malfunction drill with mag replacement and slammed home the mag? If so, you recognize the size of the mag and the way the butt plate or bottom of the mag itself is generally designed to stop the magazine at a certain point. With the larger mag you may squish it up into the workings of the gun so far that it is no longer a malfunction issue and pushed it to the point of non-working jam.

But it's up to you.

 

[Gary G23]

"will a full size M&P 9mm magazine fit and function in a M&P Compact 9mm?"

Yes it will.

I don't know about the Sigma.

 

[The Lone Haranguer]

will a full size M&P 9mm magazine fit and function in a M&P Compact 9mm?

Yes. It will of course stick out of the grip.

and then (likely in your opinion, if you happen to have seen them) will a M&P magazine, apart from base plate interference, fit and function in a Sigma?

Improbable.

 

[Disaster]

The full sized and compact M&P mags are interchangeable. That is you can put a full sized M&P mag into a compact M&P. Your best bet for checking whether a M&P mag fits in a Sigma is to go into a store that sells both and try them. If they do, it might make for a good conversion. If the mag retainer spring is the same, you might be in for some problems. On the M&P full sized, if you trimmed the grip you would be cutting away at the bottom of the retainer for the spring.

 

[mr.72]

Thanks for the tip on the retainer spring Disaster. This is just the info I was looking for.

It appears the biggest difference in the mags other than the base plate shape/angle/location is the ambi notch on the M&P mags.

I'm just thinking out of the box a little bit. I'm not sitting here with hack saw in hand I am leaning heavily towards just getting another smaller carry gun but I figured this option may be a good one not just for me, but for others as well.