[boilergonzo]

It was that the screw type lights were stiffening the frame causing less flex. This allowed the slide to travel faster to the rear and back into battery. It was doing it faster than the mag could get the next round up. That is why they later added the extra coil to the mag springs. They Gen 4 double spring was also meant to help with this issue.

Ahhh... so the flex of the polymer actually slowed the slide, so removing that flex and allowing it to cycle too fast was the issue? Fascinating!

 

[pgg00]

Ahhh... so the flex of the polymer actually slowed the slide, so removing that flex and allowing it to cycle too fast was the issue? Fascinating!

Yep. You need to treat police officers like you would army infrantry or marines. If there is a screw they will tighten it down until it strips. A bolt will be tightened with a 10 foot cheater bar if they can find one. When told to apply torque they will attempt to use all of them 🤣


The lights were meant to be finger tight then a quarter turn to "lock" it thereby still allowing some flex.

 

[fastbolt]

Ahhh... so the flex of the polymer actually slowed the slide, so removing that flex and allowing it to cycle too fast was the issue? Fascinating!

That was what armorers were told when Glock was trying to field complaints about functioning issues when WML's were used in Gen3 & older duty weapons. The guns were designed to function with the known flexing action, with some amount of expected normal 'drag' existing between the slide rails and the front frame rail fixtures when frame flexing occurred. It affected the velocity of the slide cycling.

When the frames were prevented from flexing by over-tightened WML's, the slide velocity during cycling increased (less 'drag' between steel rails) and the magazine springs had a hard time keeping up and maintaining the intended 'feeding timing'. (Of course, this could also become a problem if some hotter loads might be used, which could also create faster slide run and cycling.)

That's why one of the corrections tried by Glock with the .40's included adding another coil to some model magazine springs. I remember when a local agency was having repeated functioning issues with their new G22's when WML's were attached, and the agency armorer told me that Glock was sending him new 11-coil mag springs to try.

One of the other guys I knew at that agency told me that when he saw all the functioning issues happening on their range to the cops using WML's, he just didn't attach a WML to his G22. He had no problems.

In one recert class I attended, there were 2 armorers from different agencies attending, both of whom were asking about functioning issues occurring in their issued G23's ... but only when WML's were attached. One of them said they were issuing a major 180gr load, and the other was issuing a major 165gr load. The suggested 'answer' given to both of them was to try different ammo. (Always a safe suggestion.)

Anyway, what I thought was interesting was at different times during the class, the instructor told the guy using 180gr ammo to try using 165gr ammo ... and then later suggested to the guy using 165gr ammo, to try using 180gr ammo.

 

[familyman357]

It was that the screw type lights were stiffening the frame causing less flex. This allowed the slide to travel faster to the rear and back into battery. It was doing it faster than the mag could get the next round up. That is why they later added the extra coil to the mag springs. They Gen 4 double spring was also meant to help with this issue.

Now you’ve done it. There’s a certain “slow” member here who thinks the problem was just the opposite and that Glock and Streamlight don’t know what they’re talking about. He never has an answer as to why Glock came out with a stronger magazine spring and suggested using a fresh RSA in the problem pistols. I can almost hear his ignorant know-it-all shrieking now.

Ahhh... so the flex of the polymer actually slowed the slide, so removing that flex and allowing it to cycle too fast was the issue? Fascinating!

Yep. The extra flex was probably an unintentional result of Glock’s rush to beat S&W to market with a .40 squeezed into a 9mm frame, but other than a little extra locking block slide peening it worked well enough in those pre-WML days.

 

[klt1986]

That is cool. I am very surprised that the frames do not crack at the takedown lever area where there is the least amount of material and the most amount of flex.

I'd be willing to bet if you shot the pistol enough while locked in a vise it would eventually develop a crack. Similar to some rifle stocks developing cracks when shooters secure them in Lead Sleds.