Why do some glock slides automatically release ?

[JaviPT22]

I was wondering: why do some glocks automatically come forward during slidelock reloads, while others don't? Mine only does when I forcefully seat the mag, but not everytime. Is there an area on the slide release that can be polished?

[spanky]

Some do easier. Some do it all the time, some don't.

To answer your question, I don't know.

To add a bit of commentary that you might or might not care to hear, don't get used to it if your gun does it. Get used to dropping the slide using either slingshot or the slide stop lever. You don't want to get used to slamming a mag home then have it not work when it really counts.

[ParaGunner]

Glocks have a spring that pulls the slide stop down. So when you slam a mag in it pushes the slide up and the slide stop gets pulled down by the spring.

[Duane Thomas]

I wouldn't be looking to polish anything to get this to happen. As has been mentioned, don't start depending on the slide going forward without hitting the slide release. Because if you do, eventually it's not going to happen....and when that occurs it COMPLETELY screws your game plan. Ask me how I know.

Also, literally the only failure to feed I ever had with my Glock 34 occurred during an IDPA match when I slapped in a fresh mag and the gun dropped its own slide right into a 45-degree nose up feedway stoppage. Fortunately jacking the slide completed the chambering process. My theory is that, with a partially loaded mag holding 10 rounds, slamming it into the mag well really hard caused the rounds to bounce in the mag, then the slide released before they could reorient themselves enough to feed. I have actually put a fair amount of effort into smoothing out my load so I don't insert the mag particularly hard.

[Sarge]

My M&P would do it quite easily but never 100% reliably. For that reason I never came to depend on it. When I got my new G34 I tried it to see how easy it would do it. It will not do it, no matter how hard I try. I prefer it that way.

[Dan Hefta]

Welcome to the forum. I agree with all so far, don't rely on it, it will mess with your mind.

[eric nielsen]

Wear. If you replace the slide stop, the issue often goes away or happens less. I think the part rounds off or the finish gets slick or both.

Also it depends on how well your mag spring & follower push up the stop. Sometimes they set the stop right at the edge of the slide notch.

Try each mag empty & watch as you slowly pull back the slide.

[Aircooled6racer]

Hello: You need to put a radius on the slide stop to make it come forward eveytime. Some Glocks need more or less of a radius so I can't tell you how much. Be aware that it can be made to work about 98% of the time but will not work when you depend on it the most I use it for gun games but put another slide stop in for carry. I do practice using the slide stop as well. Thanks, Eric

[JaviPT22]

Thanks all for the very informative responses. I have always made a point to manually release the slide, but always wondered why some of the really quick shooters didn't seem to have to.

[Duane Thomas]

It's because they're so quick you don't see them do it.

[vluc]

I wouldn't be looking to polish anything to get this to happen. As has been mentioned, don't start depending on the slide going forward without hitting the slide release. Because if you do, eventually it's not going to happen....and when that occurs it COMPLETELY screws your game plan. Ask me how I know.

Ask me, too! LOL!

[sbo76]

My G-37 always (so far) drops the slide when i slap in the mag. My G-34 goes to slide lock and I to have a story about why you should use the slide release. (that cost me at least 2-3 seconds this weekend figuring out why the slide did not release) I don't know why one goes to lock over the other, but I will continue to practice as if it will always go to lock.

[Corey]

this actually started happening to me more with my G21sf when i put an extended slide stop on it. not very often and usually when i really try to slam a mag home. not a competition gun for me, so its not something im looking to relay on. if i had a Glock to compete, it would be handy to have it happen, but as others have said, dont plan on it when you need it, bc it wont happen that ONE time

[BradGannaway]

It actually throws me off when this happens. I've practice so much on reloads, that my "index" is to hit the slide release while looking for the next target. If I hear the slide fall before I hit the SR, it makes me pause slightly.

I'm going to put more emphasis on "softer" reloads to make sure this doesn't happen.

[njl]

On 3/15/2010 at 7:11 AM, Duane Thomas said:

I wouldn't be looking to polish anything to get this to happen. As has been mentioned, don't start depending on the slide going forward without hitting the slide release. Because if you do, eventually it's not going to happen....and when that occurs it COMPLETELY screws your game plan. Ask me how I know.

Also, literally the only failure to feed I ever had with my Glock 34 occurred during an IDPA match when I slapped in a fresh mag and the gun dropped its own slide right into a 45-degree nose up feedway stoppage. Fortunately jacking the slide completed the chambering process. My theory is that, with a partially loaded mag holding 10 rounds, slamming it into the mag well really hard caused the rounds to bounce in the mag, then the slide released before they could reorient themselves enough to feed. I have actually put a fair amount of effort into smoothing out my load so I don't insert the mag particularly hard.

 

I've been shooting Glocks for almost 20 years, but just started practicing for and recently shot my first IDPA match.  My Gen4 G19 will do the auto-forward thing, but with a twist.  At least twice when practicing at the range, I've had it auto-forward and close on an empty chamber.  At my first match, it auto-closed once with an empty chamber, and once with partial feed jam in which I just had to help the slide close.  The ammo in both cases was 147gr (H&S coated in practice, Montana Gold in the match)...and in both cases I was using 15-round mags loaded to 10.  The mags at the match were brand new...so not weak springs.  I've done various forms of competition, but have never until these instances had any Glock auto-close and fail to chamber a round.  

 

Previous types of competition with on-the-clock reloads, were for me, a long time ago, and I was shooting either factory 115gr or my own 124gr 9mm.  For the past several years, I've primarily shot 147gr.

 

It was suggested that the easiest fix for IDPA matches is to use 10-round mags for mags 2 and 3.

[ima45dv8]

The slide stop lever (SSL) is a stamped steel part while the slide, and the corresponding slot, is a considerably harder steel. Releasing the slide from a locked position by thumbing-down the slide stop lever will eventually cause that harder slot in the slide to round over the softer top of the lever. New SSLs have a squared profile. That's why new guns, or ones with a recently replaced SSL don't release during a forceful mag change. With less-than-new engagement, the slide jumps the rounded, polished lever when a mag is inserted vigorously.

 

Do it long enough and the slide will begin to fail to lock open on the last round in a magazine.

That's not a bad thing. Just a sign of wear, easily rectified by a replacement SSL.

 

A very predictable pattern of events:  

 - Always locks open on the last round and stays they way during reloads

 - Slide locks open on last round and releases during aggressive reloads

 - Slide never locks to the rear