Alnamvet, why are you being so vague? How about providing some more useful information?
For example,
What type of gun are you using?
What model are you using?
Have you modified the mag release?
Have you modified your CMC mags?
What other types of mags have you found that work better?
Does this just happen with one CMC mag, or with several?
Do the CMC mags work in other 1911s?
Does it matter if the mags are loaded or not?
What sort of thoughts do you want from us on the issue? Do you want to fix the problem, make it so that no mags go in without the mag release being depressed, to tell you whether we think it is a good idea or not, is safe or not, or what???
As my mechanic notes, the road to repair starts with proper problem identiification and description.
Me: My car won't start.
Mechanic: What do you mean your car won't start? Do you mean you turn the key and nothing happens or do you mean that you turn the key, the starter works, but the engine never runs? Starter and engine are two separate issues.
Come to find out, my car starts fine. My engine was not well, but the starter ran like a top!