S&W mp shield will not cock with the mag in but cocks fine with mag out

[pworley1]

My S&W mp shield will not cock with the mag in but cocks fine with mag out. I have had it for several years and never had any problems. The last time I had it out, after a few shots it would not cock with the mag in and the slide did not lock back after the last round. Have any of you had this happen?

[Winger Ed.]

Sounds like its pretty low mileage. I'd do a real, real through cleaning first.
Old oil & lube turns to sort of a wax over time and will make a gun do strange things.
Especially if dust & dirt gets into the mix.

[Kai]

A friend of mine has one of these that had the same issue. I tore it apart and figured out that the cocking mechanism was bent not allowing the sear to engage. I bent the mechanism back into place and the gun functions fine. Try putting side pressure on the trigger, first to one side then the other, and cock the gun to see if it will stay cocked. This is how I figured the issue with my buddys gun as it would stay cocked with trigger side pressure. Good luck.

[pworley1]

Thanks for the replies. I have already given it a good cleaning, I will try the side pressure.