I have a SD9VE, bought new about 5 mos. ago, it's had ~400+ rounds (115gr FMJ) thru it with 4 range trips. Cleaned and lubed per manual after each use.

Yesterday at the range a few times upon inserting a fresh mag the slide released into battery. I did not touch the slide lock/release.

I assume this is not normal? What could cause it?

Thanks, Ken

__________________
SC
30yrs. EMS & Emerg. Mgmt.

I own one as well, never had that happen to me.

How hard are you inserting the mag? Could you be hitting the release with a finger? Has the problem just started or has this happened since the beginning? When the slide locks back, how high does the lock engage the slide (just barely catching the notch or is it getting a good purchase)? Have you cleaned the mags at all? Is there excess lube from cleaning?
I have heard of at least one other person experiencing the same issue.

This is, apparently, a much misunderstood concept.

I know many folks are concerned about these pistols' slide release and whether they properly lock on the last shot and are confused about their function on loading a fresh magazine.

In my view, all this concern is misplaced:

In real applications, you should never shoot your pistol 'dry': you should always drop your magazine before your pistol is empty.

The best practice is to drop the magazine with one round in the chamber and one in the magazine.

The round in the magazine facilitates a clean drop.

The round in the chamber means that slide locking never happens and your pistol is always useful.

I'm annoyed by these ' slide lock' problems: nothing proper pistol technique doesn't anticipate and resolve.

This isn't a novel idea folks.

If your training missed this idea, your training was deficient.

My M&P 9FS started doing that after ~400 rounds. I view it as an added feature and not a malfunction.

Ken,
Greetings from the upstate. With your slide off check the rear edge of the slide release (where it lays across the wall of the mag well) for wear. That rear edge could be getting worn from use. The notch in the slide that the slide release rises into is cut at a slight angle instead of being a true 90 degrees. Any rounding of the rear edge of the slide release from wear could be causing your slide to go into battery when you insert a fresh magazine especially if you are inserting the mag vigorously. The slide release is easy to replace and cost less then $10. Hope this helps.

Best Regards,
ADP3

PS - I am not annoyed.

its a matter of physics. when you slam the mag into the gun you are forcing the gun away from the "SLIDE STOP" and therefore releasing it. try inserting your mags more slowly and gentler and it probably wont happen.
its not likely an issue of premature slide or slide stop wear. happens to virtually all semi auto weapons if the mag is inserted forcibly enough with the slide locked back.

Mine only does it if I smack the bottom of the mag hard. Otherwise inserting the mag normally, it never happens. Either way, just make sure you keep you finger off the trigger when inserting the mag...

L8R,
Matt

__________________
SD40-VE owner and proud of it!

I've had my SD9ve well over 2 years now with over 3000 rds.
About a year ago I read about some shooters doing this on purpose to speed mag change & get back on target. I tried it & it did work but not consistently so I stopped, now I practice just being deliberate with the mag change but not slamming it home.
Being aware that it could chamber a round is something everyone should know.

Thanks all.

There is no apparent wear on the slide release mechanism. If there was after only ~400 rounds I'd be worried.

I'm inclined to go along with the 'vigorous' mag insertion theory. Did a few smooth insertions and it didn't happen. Then a vigorous one and still didn't happen. So it doesn't happen consistently.

Will just be aware of the possiblity from now on so it doesn't surprise me.

As an aside, I am pleased at how the weapon has smoothed out after use. Trigger, slide, mag, etc.

__________________
SC
30yrs. EMS & Emerg. Mgmt.