So, I've taken the P250 out a few times and this last trip today it started doing something a bit weird.

It's not been locking back after the 10th round. I could possibly attribute this to the mags being 16's that I had cut down to 10's.

Now, with the slide locked back, when I slam a mag in, the slide will release and chamber a round. It's never done that, but I went through 300 rounds and it did it almost every time I put a new mag into it.

What the heck?!

Sidenote, here's one of my targets. The upper middle grouping was it's own grouping... I got lazy and didn't want to change out my target. :p

http://i202.photobucket.com/albums/aa202/youbettago12/Main/target32010.jpg

Sliding home when you bump a new mag in is semi-normal. Some guns do it more than others.

How were the mags cut down to 10 rounds? That could be the issue. Have you cleaned and oiled up the rails to be sure that isn't the problem?

My 229 will shut if I really hammer the mag in. :shrug doesn't bother me just one less step I need to do.

One of two things is usually the source of the slide not locking back:

A limp grip; robbing the slide of juuust enough momentum to be held back by the magazine follower.

Or (more likely) a thumb that's holding the lever down. Move your thumbs well clear, girlie, and see what happens. Just load one round in the mags, because that's a lot more chances to see if the gun's locking open without burning through ammo.

One of two things is usually the source of the slide not locking back:

A limp grip; robbing the slide of juuust enough momentum to be held back by the magazine follower.

Or (more likely) a thumb that's holding the lever down. Move your thumbs well clear, girlie, and see what happens. Just load one round in the mags, because that's a lot more chances to see if the gun's locking open without burning through ammo.

It is impossible for my thumbs to be in the way on the 250. Also, this happens with everyone who shoots it, not just me, so the limp-grip is a no-go.

One of THREE things is usually the source of the slide not locking back:

A limp grip; robbing the slide of juuust enough momentum to be held back by the magazine follower.

Or (more likely) a thumb that's holding the lever down. Move your thumbs well clear, girlie, and see what happens. Just load one round in the mags, because that's a lot more chances to see if the gun's locking open without burning through ammo.
Weak mag springs

fixed

Ah yes... on re-reading, I sees the part about the modifed mags. Did you guys cut down the springs in the process of fabbing these 10rnd mags?

The magazine followers usually push the slide catch up and it could be worn to the point it doesn't push up enough

On the slide falling on the just inserted magazine issue; you could be twisting the magazine as you put it in and it hits the release. That can happen on a lot of guns(including the very nice Beretta PX4 storm)

Mag follower could be gummed up enough to be "sticky" which might cause it to not lock the slide back.


Or the slide lock spring could be too weak to lift the lock into place on the last round.