S&W M&P 9 Compact Magazine capacity

[Guest jwrebate]

The other night I was loading some mags for my S&W M&P 9 Compact, which holds 12 rounds. I noticed after the 12th round that there was still a lot of play in the spring. Just for fun, I tried to load a 13th round in the magazine and, surprisingly, It went in with only a slight amount of additional resistance! The feed lips were not bent or deformed in any way. I have not fired the weapon with 13 rounds in the magazine but am going to the range tomorrow. Would it be a terrible idea to try firing the gun with a 13th round in the magazine (+1 in the chamber to begin with?) I certainly would err on the side of caution if it seemed unsafe, but I really don't see why it would be.

Please feel free to offer any concerns that you may have, as there may be a negative unforeseen consequence I am overlooking.

[dralarms]

It's designed to hold 12 rounds, 13 will over compress the spring which over time will cause it to fail.

[Guest jwrebate]

Thanks, question answered. I really just wanted someone to tell me it was a bad idea.

[dralarms]

Your welcome. Should never over stuff your mag, it can and probally will lead to a failure at some point.