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Discussion Starter #1
I did a search and couldnt find it , but I forgot what causes the wear marks on the slide of the Glock 22 ? I am talking underneath it on the slide rails on the slide itself. I used to know , but I am having a brainfart and cant remember what causes it . It appears when fairly new then it stops wearing after a certain time .
 

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Those wear marks are called "slide peening". They occur when the top of the locking block contacts the bottom of the slide when firing. Slide peening occurs primarily and most noticeably on .40 caliber models. It is perfectly normal and it will wear to a certain amount and then stop. These wear marks will not have any effect on the gun's reliability or accuracy. If the edges are too sharp you can smooth them out with a file or stone
 

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Those wear marks are called "slide peening". They occur when the top of the locking block contacts the bottom of the slide when firing. Slide peening occurs primarily and most noticeably on .40 caliber models. It is perfectly normal and it will wear to a certain amount and then stop. These wear marks will not have any effect on the gun's reliability or accuracy. If the edges are too sharp you can smooth them out with a file or stone
Good consise response.
 

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My local Glock shop is a police supply store. He always has a varied assortment of used trade-in Glocks. I got friendly with his gun salesman and went down to check on peening. I went down one day and started removing slides to compare the different peening marks. You could tell old guns from fairly new just by look and in some cases the generation of Glock. It did look like, to me, that any of the Glocks that had been shot all showed the same amount of peening. There is no glaring difference.
At
 

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Discussion Starter #5
thanks guys . My 22 is 11 yrs old and after the 3rd year it has stabilized . The last 8 yrs now have been the same . I just couldnt remember what caused it . If the 9mm's had more pressure, could it too have peening ,marks? Does the more higher pressures of the .40's cause this?
 

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I just went to the armorers school and this is how it was explained to me. 9mm is a high velocity load but low weight projectile. 45 is a high weight projectile but low velocity load. The 40 is both high velocity and higher weight so its just the way the combo comes together.
 

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I just went to the armorers school and this is how it was explained to me. 9mm is a high velocity load but low weight projectile. 45 is a high weight projectile but low velocity load. The 40 is both high velocity and higher weight so its just the way the combo comes together.
<3 .40 s&w
 

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Are you talking about the sometimes deep cuts on both sides on the underneath portion of the slide inside of the rail recesses at about the location above the beginning of the frame's locking block? That was caused by the original style locking blocks Glock used to have. The old blocks incorporated a shoulder in their design which would be lifted up somewhat during firing as the underlug of the barrel contacted the ramp of the locking block -- enough for the sharp edge of these shoulders in the block to gouge the portion of the slide with which they would contact. Over time, it would dig enough volume out of that portion of the slide (on both sides) to where it no longer contacted it and the problem would seem to end. The damage was completed. Luckily it did not seem to harm the function of the gun and so no one suffered any severe consequences.

This happened more with the the higher powered calibers as the slide velocity and force was greater. But this phenomena was ended once Glock redesigned the locking blocks to no longer have this sharp 90 degree shoulder and instead added length to the front portions of the locking blocks. Unfortunately, this smooth shoulderless stretch of locking block was kind of on the thin side and not supported as well with the pins and was somewhat prone to breakage. So Glock thickened them up a little bit I believe. These redesigned blocks would be lifted slightly during firing (like the old ones) and would contact the slide on the front portion of the block and this would be a point of stress which could cause breakage (to the block) over time (as I said, I believe Glock has since thickened the front extensions a bit, ending or at least decreasing the likelihood of the problem). But since there was no shoulder to grab the underneath of the slide, this contact would merely cause two slight rub marks to the slide where the old style blocks would dig in and gouge the hell out of it.
 

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I use 20# recoil springs in my Glocks for range use. I believe this stronger spring changes the frame flex so that it doesn't contact the locking block quite as hard. I do know the peening that I had, stopped with the 20# spring.
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Discussion Starter #11
I just went to the armorers school and this is how it was explained to me. 9mm is a high velocity load but low weight projectile. 45 is a high weight projectile but low velocity load. The 40 is both high velocity and higher weight so its just the way the combo comes together.
Very good information and explanation, thanks
 

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Discussion Starter #12
Are you talking about the sometimes deep cuts on both sides on the underneath portion of the slide inside of the rail recesses at about the location above the beginning of the frame's locking block? That was caused by the original style locking blocks Glock used to have. The old blocks incorporated a shoulder in their design which would be lifted up somewhat during firing as the underlug of the barrel contacted the ramp of the locking block -- enough for the sharp edge of these shoulders in the block to gouge the portion of the slide with which they would contact. Over time, it would dig enough volume out of that portion of the slide (on both sides) to where it no longer contacted it and the problem would seem to end. The damage was completed. Luckily it did not seem to harm the function of the gun and so no one suffered any severe consequences.

This happened more with the the higher powered calibers as the slide velocity and force was greater. But this phenomena was ended once Glock redesigned the locking blocks to no longer have this sharp 90 degree shoulder and instead added length to the front portions of the locking blocks. Unfortunately, this smooth shoulderless stretch of locking block was kind of on the thin side and not supported as well with the pins and was somewhat prone to breakage. So Glock thickened them up a little bit I believe. These redesigned blocks would be lifted slightly during firing (like the old ones) and would contact the slide on the front portion of the block and this would be a point of stress which could cause breakage (to the block) over time (as I said, I believe Glock has since thickened the front extensions a bit, ending or at least decreasing the likelihood of the problem). But since there was no shoulder to grab the underneath of the slide, this contact would merely cause two slight rub marks to the slide where the old style blocks would dig in and gouge the hell out of it.

Were these newer styled locking blocks just made on the 40's or all across the board on 9mm, 10mm's , .357's ,.45's and so on?
 

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Were these newer styled locking blocks just made on the 40's or all across the board on 9mm, 10mm's , .357's ,.45's and so on?
All across the board. And you can tell by looking at them when field stripped.

Interestingly, when I sent my early Gen 2 G22 for a separate problem, instead of fixing the problem (cracked rear frame rails...they would have to replace the whole frame obviously, with all of the legal headaches of Kalifornia), they replaced all the innards, including the locking block. To make the new style block fit, they had to change the housing shape of the slot in which the block sits in the polymer frame. While they did an impressive job, I still have the original problem and have not figured out what I am going to do about it yet...I'm pretty busy at the moment.

The rails cracked on the rear portion because they were the old/new style of longer rear rails which don't like the frame flex of G22's. Glock has since gone back to the shorter rear rails, as witnessed in my much later G20, circa 2005. Pretty much only G22's with the longer rear rails suffered from the problem as the compacts have the front and rear rails spaced closer together and the perils of frame flex are less of a problem. Frame flex is why I always wish that Glock would go to an integral chassis system ala Steyr, S&W (M&P), Kel-Tec, Sig (250), etc. They could also make silly legal hassles less of a problem by designating the chassis as the frame and the polymer as a shell (like Kel-Tec does).

Sorry about the drift, but I figured you might ask about what I was alluding to.
 

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I just went to the armorers school and this is how it was explained to me. 9mm is a high velocity load but low weight projectile. 45 is a high weight projectile but low velocity load. The 40 is both high velocity and higher weight so its just the way the combo comes together.
Who was your instructor? Jim Greene?? Cause I just finished the armorer school and that was what they told us, almost verbatem. :supergrin:
 

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I kind of like the slide peening on the .40 S&W Glocks - it helps me get good deals. Just today I stopped by a shop that got a fresh load of G22 trade-ins. I just stripped the slides until I found the one with the least peening. You can always tell which has been used least.
 
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