slide lock releases when I insert magazine 1911

[JDGray]

I slam my mags home fairly hard

This will cause your problem, especially if your stop isn't making full contact with the notch in the slide.

Report back when if you fix it

 

[xmanpike]

Well I have been playing with my gun and disassembled and cleaned as always, and the problem seems to have gone away. For some reason the mag follower was not engaging the slide stop with enough force to fully seat it.

Question. After looking carefully the slide stop does not have the same shape as the slide stop notch. Is this normal?

Also.....I read some people have a small dimple where the slide stop plunger sits on the slide stop. I have no such dimple or number or whatever. is this part of the problem?