S&W 380 Bodyguard - During Mag Changes at a range session, smacking mag in, the slide releases and goes into battery - 4 of 5 times. Slow gentle mag change was ok. This was a NIB Pistol.

Happened on a Used recent purchase S&W 9mm Pro as well - almost the same symptoms.
Very Odd compared to other Pistol Mag Changes I've had experience with.

Had a S&W 45 double stack that was consistent and never Auto Released during our session.

Anyone else see this as an odd or dangerous action - It surprised me when it happened but if I was in a competition I would have appreciated it.

This question has often arisen about other guns. It’s so common with Glocks that many users depend upon its happening when reloading at speed. The mechanism that causes it is very simple: If sufficient force is applied to the butt of the gun that the frame is driven forward while inertia keeps the slide from moving, that will release the slide catch and permit the slide to move forward.

The only disadvantage of its happening is that if it’s common enough, users start depending upon it rather than releasing the slide manually. When it doesn’t happen they may become confused and not release the slide as they should.

In my experience it is common not only with Glocks, but also S&W M&P models. It is not common with SIG Classic line pistols, but not impossible or unheard of.

I have had this happen on other guns. (I don't remember for certain which ones. My current SIG and two CZs do not.) This is only a problem if it fails to chamber the round.

Yes several discussions on this topic.

https://sigforum.com/eve/forums...850020144#6850020144

quote:

Originally posted by drabfour:
Yes several discussions on this topic.

https://sigforum.com/eve/forums...850020144#6850020144

People forget this gun forum actually has a pistol section.

My H&Ks do it. I like it and, as sigfreund has said, I have come to rely on it.

When running a P320 in a class I was a little over-enthusiastic and was getting regular “birthday bumps”. I thought it was cool until the one time when it didn’t pick up a round. After that, I made a concerted effort to avoid them.

This is my favorite feature of my M&P pistols. Auto release of the slide when aggressive mag change is done = perfect function of a semi-auto Seriously, if only my single stack 1911's would cooperate.

Very common.

As are the posts of “Is it a feature or defect”?

Thanks to all who commented, I was just a shooting companion and evaluating these new to my buddy guns. I am not a Stricker/Polymer guy as yet.

I did follow the past posts as well and concur with the posts - My vote is: I don't like surprises - Ever. Yes I do shoot USPSA and understand every fraction of a second counts - but - consistency of action is paramount to me.

It is common. But I was always told / taught that slamming in a mag can be damaging to mag and gun.
Wanna see the classic "mag slam"? The opening segment of the original Magnum PI. Selleck slams the crap out of a 1911 mag.
Cant say I saw him do it to his high $$$ Gunsite 1911 in the Jesse Stone movies.

To help avoid its happening, the force in seating the magazine should be in line with the mag well, and not against the bottom rear of the grip.