When popping in a new magazine, I’m finding that the slide disengages, and chambers the new round.
The only motion is the magazine being inserted, and thats sufficient to send the slide forward and the pistol in to battery.
What would cause this?
I call that a feature. My Glock 19 and M&P do this.
It’s an “undocumented feature” 
No surprise about that comment coming out of a Microsoft guy 
It happens occasionally on a couple of my Glocks.
As a lefty I think it makes a great feature to have on any gun :))
It’s often referred to as “auto-forward” and it can happen with just about any handgun if you insert the magazine at just the right angle with enough force. It is far more common on polymer framed guns because they flex a bit when you slam a mag in.
As long as it always strips a round it’s not a bad thing. However, I have seen literally dozens of shooter rely on this “feature” only to have it fail when they needed it. You see it a lot with new shooters in competition … it always works on the practice range but when you add movement and stress somehow it just doesn’t happen and you get bit in the ass.
Most shooters also fail to practice for this eventuality. So the process goes like this:
[ol][li] Slam mag into gun to reload, expecting auto-forward.
[/li][li] Press gun out to target.
[/li][li] Get no BANG.
[/li][li] Start immediate action drill by tapping mag.
[/li][li] Go to rack slide for immediate action drill, discover slide is already locked to the rear (doesn’t feel right).
[/li][li] Stop and stare at gun.
[/li][li] Begin thinking about others ways to make the slide go forward.[/ol]
[/li]
I’ve had students in class who, upon being warned this was a bad technique to rely upon, happily informed me that it always worked for them. Then the next time they perform a test under stress (usually the F.A.S.T.) the slide fails to auto-forward. People have a really weird concept of “always” when it comes to guns.
It really shouldn’t be doing this every time. I really have to slam mine at the correct angle (basically the same as with my Glock) to get it to work. Personally, I am a slide release guy.
People have a really weird concept of “always” when it comes to guns.
God knows that is true.
Though auto forward may be viewed as a potentially valuable feature to some, I personally find mechanical consistancy more preferable.
Not a “might go in to battery, might not.”
Popping in a magazine almost always sends the slide forward. I’m tempted to say “always…period” but I agree with ToddG’s assessment above.
There is also a perception that auto-forward is “faster,” but that’s only going to be true if you’re doing a poor reload to begin with.
No kidding. I was taught and I practice running the slide even if it falls upon inserting a new mag. If I eject a live round, so be it. I’d rather it be that and have the insurance than have a firing pin hit an empty chamber. I overhand anyway for every reload so it’s not wasted motion for me.
My experiences/Training/3cents worth…
I too have experienced this “feature” on different custom 1911s, SIGs and HKs. A forceful or “situation excited” slide lock mag change will induce this on occasion.
John Farnum’s Advanced Defensive Handgun classes teaches to rack the slide ANY time a fresh mag is inserted in a slide forward situation. Wasting one questionable loaded round to assure positive ready condition is a must. I feel it applies to this automated situation as well.
Solid fundementals get the job done. Gross motor skills/gun handling manipulations get it done. For me the lever is a Slide catch not a release.
Harold H.
I’d call it a flaw more than a feature. If it did it every time I could believe someone designed it like this on purpose, however the only pistol I’ve ever shot that does this is a glock, and it only does it about 30% of the time. I’m sure some of it is operator caused by me, but I’d prefer it never did it at all, as I’ve been taught to rack everytime after I insert a mag.
I agree with M4tographer
Agreed.
I’d say for one gun to do it 30% of the time that is indeed a concern. I have had it happen a single digit of times in six different guns over many years. For me a rarity.
In your opinions what factors may influence the auto drop effect ? Over insertion of mags ? In some gun designs weak/worn springs ? What else ?
During a 2.5 day Farnum class I was using a Officer framed/Commander slided custom 10mm. In about 700-800 rounds the slide never followed on a mag refresh. The mags I was using where chopped down Metalforms with the base plates welded on to the tube. The base plate tabs on all four mags were bent down. Luckily the mags were hand made with the bottom plates fully welded to the body. When you are pumped up the forces you exert on mechanical devices are Huge. I have broken more than one stock Mec Gar 10mm mag. Had a shop rat weld them on for me.
I have had the autodrop feature happen more on my two HK’s and one Xd than I have on my custom 1911’s. Leads me to think design. I have seen in happen on Glocks as well.
My experiences.
H
If you read your HK manual you might discover that it is a documented ‘feature’.
“If you read your HK manual you might discover that it is a documented ‘feature’” What !!! How dare you Limey accuse me of failure to read the HK manual …:eek: wait, I didn’t, I just looked at the pictures … No I breezed thru them.
I just did a quick word search in a USP compact manual and did not see (by my chosen words to search by) anything. Or I overlooked it.
H
Well done Limey …
Case closed.
H
Well, that manual hardly seems to be advertising it as a feature. LOL.
Yes, this seems to be a phenomena largely (but not entirely) confined to polymer guns.
That manual reads as a warning and by no means a feature.
It’s somewhat amazing to me, for a site with membership that goes ga-ga over reliability features on AR’s, this case of mechanical inconsistancy gets a shrug of the shoulders essentially. And apparently its somewhat common and not exclusive to HK45’s. Maybe we need a chart for pistols too. No reason, IMO, they shouldn’t be held to very similar standards. Mechanical tools should operate as completely reliably and predictably as possible. Period.
I still love the gun…just seems rather odd this goes unaddressed. Maybe I’m missing part of the picture here.