Automatic Slide Release??

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Rule3 said:
Some OCD comp shooters, remove the slide lock and count their shots, drop and insert a full mag with one round left in the pipe.
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We USPSA shooters don't count our shots, we "break down the stage" and know where we are going to reload before ever firing a shot. I have fired 16 shots out of a 17 shot magazine and done a "Cooper reload" with only the round left in the chamber, but I have also fired as few as 4 and abandoned a 3/4 full magazine because a reload then, moving between target arrays, left me in shape to finish the stage without another reload.

On the other hand, IDPA requires you to shoot to slide lock (or perform the sleight of hand Tac Load) and the Auto Forward becomes a factor.
 
JTQ said:
They stiffened the frame with a longer steel insert, redesigned the slide stop, and changed the frame around the slide stop to keep it in place

Original M&P https://www.smith-wesson.com/firearms/mp-9-magazine-safety-tritium-night-sights-le

M&P 2.0 https://www.smith-wesson.com/firearms/mp-9-m20-15-rds
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It took 10 minutes of research to find out you are pretty much wrong on all accounts. The defect is with the m&p failing to chamber a round when auto forwarded, unlike pretty much every other pistol before it. They couldn't solve the chambering issue so they added a detent to keep the slide release in the locked position while reloading. When racking the slide, there is actually a hump and notch that force the release down. Basically they had to make a new design to fix their flaw.
 
MCFLYFYTER said:
It took 10 minutes of research to find out you are pretty much wrong on all accounts. The defect is with the m&p failing to chamber a round when auto forwarded, unlike pretty much every other pistol before it. They couldn't solve the chambering issue so they added a detent to keep the slide release in the locked position while reloading. When racking the slide, there is actually a hump and notch that force the release down. Basically they had to make a new design to fix their flaw.
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What was your question?

I was answering how S&W stopped their M&P 2.0 from auto forwarding, which is what I believe your question was and is the topic of this thread. Auto forwarding and whether the gun picks up a round when it auto forwards are two different issues.

The changes I listed were things S&W did to prevent the gun from auto forwarding.
 
You stated that auto forward was a defect. To say that every other pistol design is defective is a stretch at best.
JTQ said:
The changes I listed were things S&W did to prevent the gun from auto forwarding.
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Do you have any documentation to support the above statement?
 
MCFLYFYTER said:
Do you have any documentation to support the above statement?
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I don't now, but I was pretty sure it was common knowledge by now.

When the 2.0 guns were released, nearly every article made mention of the changes to stiffen the frame, and the redesigned slide stop lever that will put an end to the auto forwarding. Whether it is a problem or not, S&W seemed determined to stop it from happening.
 
Nothing is common knowledge, such questions get asked every week.

I would not want a Plastic M&P 2.0 because while they did away with Auto Forward, they did not make the slide stop lever any more prominent. Also because they did away with the beavertail and made the grip texture very rough.
 
Jim Watson said:
Nothing is common knowledge, such questions get asked every week.
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True, I suppose.

After I made the common knowledge post, I began to think if somebody were to ask me for documentation that S&W made the original M&P because they were lighter, less expensive to produce, easier for the end user to work on, etc., than their previous generation of metal framed TDA guns, I wouldn't be able to come up with documentation for that either.
 
Jim Watson said:
I'm waiting on a pistol that will automatically drop an empty magazine like a Garand spits out an empty clip.
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Cobalt Kinetics figured it on AR-15's... Perhaps they will do the same to 2011's one day????
 
Some people will debate or argue about anything. "Auto Forward" is not a design feature. I guess if discussed enough it will be.

It is called a slide STOP, not a "some times auto forward". No owners manual from SW, Sig, Glock ,Beretta describe using such a feature like it's a good thing. Maybe some folks think its great and use it for speedy reloads. So be it.
A gun is not designed to do it
Why not have a Auto Fire so you can slap the bottom of the grip and the gun goes off?

Been the same arguments since around 2011 or earlier

Here read page 18
https://snwcdnprod.azureedge.net/sites/default/files/owners-manuals/M&P_M2pt0_Pistol_031220_3012548.pdf

WARNING: DONOTUSEExCESSIVEUPWARDFORCEWHENINSERTINGALOADEDMAGAZINEINTOTHEPISTOL. EXCESSIVEUPWARDFORCECOULDCAUSETHE SLIDETOMOVEFORWARD, CHAMBERINGAROUNDANDMAKINGTHEPISTOLREADYTOFIRE
 
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Monac said:
I cannot remember if the slide release on the FN 1903 was set up to work that way.
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On my original FN 1910 .32 acp the slide does not stay open after the last shot and it does not load a round when a new magazine is inserted even if the slide is held open manually and released manually. A new round is inserted only when the slide is hand operated. It may be different on the 1903.
 
The Mauser HSc "slide lock" is the magazine follower (as it is on many of the early pocket .32s and .380s), the "slide hold open" is a little lever that gets lifted as the magazine is withdrawn, and should be in position to prevent the slide from going forward. On insertion of a new magazine, the "slide hold open" lever is pivoted down by the top of the magazine, releasing the slide. The problem is that after a little wear, the slide will not stay open as the magazine is withdrawn, sort of the opposite problem the OP has . . .
 
lysanderxiii said:
The Mauser HSc "slide lock" is the magazine follower (as it is on many of the early pocket .32s and .380s), the "slide hold open" is a little lever that gets lifted as the magazine is withdrawn, and should be in position to prevent the slide from going forward. On insertion of a new magazine, the "slide hold open" lever is pivoted down by the top of the magazine, releasing the slide. The problem is that after a little wear, the slide will not stay open as the magazine is withdrawn, sort of the opposite problem the OP has . . .
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Thanks, lysanderxiii. The Mauser HSc I had was one of the early post-WWII ones made for the French. It was very well made, and had very little wear, so the slide locking open when empty, remaining open when the empty mag was removed, and closing as soon as a loaded magazine was inserted worked perfectly, but I always thought it was over-engineered and needlessly complex. I am not surprised to hear it got finicky fast. That may also explain why it is not deliberately designed into many guns.
 
I dont think it has anything to do with grip angle.
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Not grip-angle, per se, but it does have to do with the angle that the magazine goes into the gun. If it goes more or less straight up into the grip, you're less likely to get the slide to drop on a vigorous mag change. If the mag goes in at a significant forward angle, it's much more likely.
This happens occasionally with some pistols, often polymer framed guns and 1911s, and it is not a feature, it’s a defect.
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It's more likely with some guns than others, but it can happen with virtually any gun with conventional slide release because of how the slide release works and due to the physics of inserting a magazine vigorously.
If the force required to do it is low enough it could be considered a defect, but it's the nature of relying on friction to hold open the slide.
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Yes and yes. It shouldn't happen with a "normal" mag insertion, but if a mag is slammed into place, as is common in a quick mag change, it's going to happen sometimes--it's just the way the system works.
"Auto Forward" is not a design feature.
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I agree. I don't believe any manufacturer intentionally designs their guns so that it happens. It's a byproduct of how the system works, not an intended design feature.

Just so it's clear, I'm not talking about one or two handgun designs where the manufacturer states that normal operation means that a magazine insertion drops the slide and chambers a round. I'm talking about typical semi-autos with conventional slide releases.
 
Seems a peculiar argument some are making; if you reach empty and the slide stop catches, in what instance are you not intending to chamber a round when inserting a fresh magazine? Whether you depress the lever or slingshot the slide the net result is the same, a loaded chamber. That can be the only intention. If you don’t want a chambered round, drop the slide before inserting the magazine.

My first M&P’s slide stop was nearly impossible to use as the slide notch offered a sort of concave profile at its upper edge and the stop flexed considerably before overcoming the spring pressure. The opposite (weak) side could not function at all as it ran out of room at the frame without releasing. Some careful filing fixed the problem and induced auto forwarding when firmly seating magazines. More than once I’ve read that firmly planting the mag is what you should train to do and for the record my M&P never failed to chamber a round.
 
A relatively new Russian automatic "Udav" also loads upon inserting a new magazine, in the way of Mauser HSc. The mechanism works no matter how gently or briskly the magazine is inserted.
 
My HK USPc and Bersa T22 do this routinely. Probably others too I just don't recall. Not a problem as far as I'm concerned.
 
My P365 SAS does not do it but my CZ 75B Omega will at times when I slam in a magazine.
 
I did not know that the M&P 1.0's did so until last week when shooting with a friend and his brother, both of whom have them in .45 ACP. The first time I saw it happen, I asked to see the gun. It did it even when I deliberately did not 'slap' the mag in as I usually do with everything else. They both swore up and down it was a design feature, the salesman at Fleet Farm told them it was. :confused: I have had Glocks do it when I slapped the mag in, but not all the time. I have shot an HSc, and knew of that feature when I did. (I am not enamored of it, I prefer to use a slide stop, 1911 bias showing.)
 
JohnKSa said:
Not grip-angle, per se, but it does have to do with the angle that the magazine goes into the gun. If it goes more or less straight up into the grip, you're less likely to get the slide to drop on a vigorous mag change. If the mag goes in at a significant forward angle, it's much more likely.It's more likely with some guns than others, but it can happen with virtually any gun with conventional slide release because of how the slide release works and due to the physics of inserting a magazine vigorously.Yes and yes. It shouldn't happen with a "normal" mag insertion, but if a mag is slammed into place, as is common in a quick mag change, it's going to happen sometimes--it's just the way the system works.I agree. I don't believe any manufacturer intentionally designs their guns so that it happens. It's a byproduct of how the system works, not an intended design feature.

Just so it's clear, I'm not talking about one or two handgun designs where the manufacturer states that normal operation means that a magazine insertion drops the slide and chambers a round. I'm talking about typical semi-autos with conventional slide releases.
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Sounds like you understand what is actually going on here. The auto forward really started to be common with polymer frames. The lighter the frame and the heavier the magazine, the more likely the frame will bump forward of the slide and let the stop drop.

By my calculation there are 4 things that really affect auto forward
Ratio of frame to slide weight
Recoil spring pressure at slide lock
Angle of force applied by magazine insertion
Weight of loaded magazine
 
mcb said:
My XD-40 will do this pretty reliably for me though I do my best to never shoot to slide lock. Reloading with a round still in the chamber is faster.
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Me too, people laugh at me because to do it I need to take off my shoes when I shoot full sized autoloaders, not an issue with a compact. Dang standard capacity modern guns.
 
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The more inertia in the slide, the more likely it is to stay put. That's important.
The lighter the frame, the more likely it is to move when bumped. Also important.
The strength of the recoil spring makes a difference. The harder it is to compress, the less likely the gun is to drop the slide.
The angle of the bump is critical. A straight up bump isn't going to do anything--it has to move the frame forward to take pressure off the slide lock.
It takes a significant bump. How much depends on the gun.

Just for fun, I tested some different guns and all of the ones I checked could be bumped on the grip so that the slide would close from slide lock.

Ruger 22/45 (No slide--internal bolt)
Walther PPK (.380ACP) (Heavy recoil spring, steel frame, light slide)
Glock 17 (Light frame)
Ruger P95 (Light frame and recoil spring)
CZ-75B (Steel frame)

The Walther probably required more of a bump than any of the other guns. The Ruger 22/45 was probably next with the CZ (steel frame) following. The two polymer frame centerfires didn't require much force.

I seriously doubt anyone would be slamming a mag home in either a Walther PPK or a Ruger 22/45 with enough force to cause the slide to bump closed--I just thought it would be interesting to check them to see if it was even possible.
 
I'm in the camp of people who never use the slide stop unless it's a range requirement to open the action and insert a chamber flag. Besides that one circumstance it's an utterly useless to me, it's a function that should be in all bottom feeders but if it weren't there it wouldn't hurt my feelings
 
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