M&P.40 mag springs

[Defense Minister]

I have two M&P .40s, one full-size, and one compact. The compact mags hold 10 rounds, and the full-size mags hold 15. When I used to load the compact mags up with the full ten rounds, the tenth round was extremely difficult to insert into the magazine, and the fully-loaded 10 round mag was extremely difficult to insert into the mag well. So, I have been loading the mags with only 9 rounds. Then I got to thinkin'...

I disassembled one each of the full-size and compact mags, and just as I had begun to suspect, the springs were exactly the same length. So, I went to the "experimentation" table (my workbench). I cut two coils off of one of the springs and reassembled the compact mag with that spring. It would still only hold ten rounds, but the last one was much easier to insert into the mag, and the fully loaded compact mag now goes into the mag well much easier.

I don't know if all the compact mags come with the full-size spring or not, but I thought I would pass this along in case anyone else was experiencing the same thing. Cheers!

 

[71Commander]

Thanks. I'll be choppin today. I'm gonna start with one coil though.

 

[MT GUNNY]

I did the sam thing, and it helped with the 15th Round. Just be Careful not to distort the Natural Shape of the Spring(especially in the .45) If you Do the Coils will hang up on each other in the Mag and willl cause some Problems. Don't ask me How I Know!

 

[The Lone Haranguer]

I note that you have apparently not yet shot the pistol after doing this. I would carefully and thoroughly test the mag(s) for reliability before putting them to work. You may find that you start getting feeding malfunctions. (Hopefully not.)

 

[Hungry Seagull]

Hm. I was thinking 9 is plenty. I hope when you do shoot and get to that tenth round it still has enough spring to feed chamber.

Something for me to think about as I am divided between compact 10 and full size 10 at the moment.

 

[Defense Minister]

I actually cut only one coil off to begin with, but it made very little difference. So, I went with two and liked the result.

I haven't actually fired the gun with the cut springs yet, but when I load the first round in the compact mag with the cut spring, there is still more tension on it than on the first loaded round of the full-size mag with the uncut spring. Therefore, I am about 110% sure that spring tension with the cut springs will not be a problem.