[TheOtherOne]

I clean the gun everytime after I shoot it and this is the first time I've noticed these marks on the slide. Either I just wasn't paying attention before or it's new since I shot last week. I've probably got about 500 rounds through the thing.

http://u.cc.utah.edu/~gmj06b50/Guns/G27-SlideMarks.jpg

I always clean it and lube it with Breakfree CLP. Once all the factory copper lube stuff wore off... CLP is the only thing that's been on it. Good or bad?

[Handy]

Well, it's not good. I'm willing to bet you have a Glock 35, but this type of slide peening has been seen on other models.

These marks are caused the frame block (where the barrel rests) rocking up during the recoil cycle and hitting the slide. Sometimes it gets no worse, but many 35 owners have had to file some of that off because it starts to interfere with the barrel. You'll just have to wait and see.

Good picture.

[TheOtherOne]

It's not the Glock 35 but it is a .40 caliber. It's the Glock 27.

[NJ3]

Those marks are common. All 4 of my Glock .40's had them.

CLP is fine too.

[NJ3]

Here is a link I found on slide peening.
Click Here (http://www.custom-glock.com/peen.html)

[TheOtherOne]

Those marks are common. All 4 of my Glock .40's had them.

CLP is fine too.

Thanks. I was wondering if maybe this was some side-effect of not using the copper lube or something.

Good to know it's a normal thing.

[gudel]

is that an actual dent on the slide or just some marks? can't really tell from the picture.

[TheOtherOne]

It's actually worn down the metal some. Not very much, but some.

[JohnKSa]

Common in the heavier recoiling models. Rarely a problem.

[RON in PA]

Every Glock that I've owned, 4 9mm and 1 45 ACP had slide peening. It is a common question and concern at Glocktalk. No problem.

[GLOCKT]

All 3 of my Glocks .40sw have to same peen marks.
G27 and both G22 and G22c.
They have nearly 8k fired thru each.
The peening stopped somewhere around the 700 round mark.
It's been addressed with the local armourer and said it was a concern with the .40sw but the reliabilty factor was not comprimised and the caliber will shoot in the upper 30k rounds count.Then consider rebuild,internals only.
He told me if it was to become a personal issue take a small file and file away the channel.The indent into the slide will not affect the function or accuracy of the pistol.

[TODD3465]

Checked all of my Glocks 17L, 34 and 23 all have the same deal and all seem to match rub marks on the barrel locking block(?) on the frame.
My 34 which I've shot less than the other 2 has a deeper mark but the block on the frame has higher points on it.
I'd just say it's normal break-in/wear for this gun.

[Tamara]

My G29 has shiny marks in the black coating there, but no discernable wear in the metal.

[ChickenHawk]

My G17 has similar marks.

I showed them to the Glock Armorer at the GSSF match in Carrolton, TX a few weeks ago. He told me they are normal and not to worry about them.

They are caused by the slide rubbing on the locking block. If it feels rough to your finger you might file it down just a bit.

Cheers,
ChickenHawk

[Nero Steptoe]

I shoot a lot of hot stuff out of my G21's and G30. Also shoot a G17. None of my Glocks has slide peening. In my humble opinion, using a proper (read: heavier-than-stock) recoil spring weight, that's more appropriate for the .40's would lessen or stop the peening.

If your Glock's ejecting brass further than 4' to 6', you need a stronger spring.

[T.Stahl]

I just checked my 17L, which has seen about 8,000 rounds of mostly +P ammo. I noticed the marks for the first time after a few hundred rounds. Now they are a bit larger than TheOtherOne's, but I don't worry about them at all.