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Discussion Starter #1 (Edited)
I was at the range earlier and had the slide locked back, then picked up my Gen 5 G17 and noticed the striker was free to fall full forward and rearward looking on the bottom of the slide at the rear. I could flip it forward and back with my finger. Is this normal on the G17 Gen5? With my G19 Gen3 and G26 Gen4 the striker will not move when the slide is locked back.
When I slowly move the slide back into battery with the striker pin full forward through the recoil shield the striker moves back into the channel rearward.
I never ever noticed this before with any other Glock but perhaps I missed it on previous G17's?


Just talked with Glock Tech support and the Gen5's and the 42&43 should freely move back and forth with the slides locked back. Other generations shouldn't
 

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Answered by Glock tech support......."normal"
That doesn't tell you WHY the design was changed to depress the Firing Pin Safety (thus allowing free movement of the FP) when the slide is retracted. What follows does.

There is only one reason that the post-Gen4 Firing Pin Safety gets depressed as the slide is retracted. It is a direct consequence of using a compressed Trigger Spring in the post-Gen4 Trigger Mechanism Housing.

1. Post-Gen4 pistols eliminate a problem that has haunted every Glock pistol ever made before the G42...failure of the coil Trigger Spring hooks. Hook failure of the streched Trigger Spring has always been THE most common part failure in Glock pistol history. In 2010 the new Gen4 design kept the same Trigger Spring, but altered the TS hook attachment point on the Trigger Bar and on the Trigger Mechanism Housing to reduce localized mechanical stress on the inner surface of the hook. The same improvements were made in new Gen3 pistols and Gen3 TB and TMH parts. Still, some possibility of Trigger Spring hook failure remained in the stretched spring design.

Post-Gen4 pistols beginning with the G42 completely eliminate the old stretched TS and the hook attachment points on the TB and TMH. The new TS design is now a hookless compressed spring assembly that is an integral part of the post-Gen4 TMH.

2. The new TMH had to have its polymer right side raised in order to provide sufficient structure to support the new internal TS assembly.

3. The Post-Gen4 slide rides freely over the raised right side of the new TMH, except for the Firing Pin Safety. A polymer ramp has been placed on the front right side of the TMH to lift the Firing Pin Safety and allow it to ride smoothly over the raised right side of the new TMH. This lifts the FP Safety and results in free movement of the Firing Pin when the slide is retracted.

4. An enlarged clearance cut in the lower right side of the Slide Cover Plate is required to accommodate the raised right side of the post-Gen4 TMH.

There is NO purpose served by the depressed FP Safety during slide retraction other than to allow it to pass over the top right side of the TMH as the slide retracts. The FP Safety must be raised because of changes to the TMH needed to implement the post-Gen4 compressed Trigger Spring design.

FWIW, a Gen4 slide with Gen5 Slide Cover Plate can be physically fitted to a Gen5 frame (except Gen5 G17 and G34 frames because these now use G19 barrel lock-up). But this should NOT be done. The Gen5 FP safety is ramped front and back to properly ride the polymer ramp on the right side of the TMH. The pre-Gen5 FP Safety is not shaped properly for the post-Gen4 TMH ramp. Its rounded shape will likely cause abnormal wear on the polymer TMH ramp.

FWIW, the post-Gen4 Firing Pin Safety bearing surface does NOT require precise left-right Trigger Bar positioning under the FP Safety for reliable lift during trigger pull.

Gen4 pistols require the TB alignment bump when the Magazine Catch is installed on the right side of the frame. In that position the Magazine Catch and Spring may twist the top right side of the Magazine enough to rub the left side of the Trigger Bar during trigger pull. The Gen4 Trigger Bar alignment bump prevents the Trigger Bar from misaligning to the right enough to inadequately lift the circular-shaped Firing Pin Safety.

The post-Gen4 FP Safety bearing surface is not the beveled flat circular surface used in all earlier models. It is now a ramped ridge from left to right. No matter where the Trigger Bar runs across the new FP Safety, the safety will always be lifted properly. Because of this, post-Gen4 pistols do not require an TB alignment bump when the Magazine Catch is on the right side...so now the bump is gone.
 

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Discussion Starter #6
Thanks Mike-M, We learn more and more the changes that were made to these handguns to be called "Gen-5's". What you posted has never been relayed to me by anyone in their review of the Gen 5's. No where I can find.
I appreciate your taking the time to explain this.
Regards, Sgt Mike
 
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