odd dent/wear marks on spent casings from g29

[novasquid]

i have 150 rounds through my g29 in it's stock form. i recently installed a wolff 21lb recoil spring and went to the range with 180gr underwood ammo. see pics below.

i never examined any casings from the g29 in its stock form, so i don't know if it's been happening from the beginning. but i had another g29 that never showed any of these marks. so i'm curious what could be causing the dent and scuff marks?

i'll go back monday to try it with the stock recoil spring, but i suspect it'll still be showing up.

http://i592.photobucket.com/albums/tt2/DHYCFI/guns%20and%20ammo/glock%2029sf%20srw257/8f5b9e1d.jpg

http://i592.photobucket.com/albums/tt2/DHYCFI/guns%20and%20ammo/glock%2029sf%20srw257/4c1cfdba.jpg

[novasquid]

the dent is showing up on nearly 100% of the 150 rounds i shot today and is consistent in its location, the scuff mark is showing up on 90% of the same rounds and varies in location from low to high, but is always the same distance away from the dent.

[Morley Menthols]

novasquid... I shoot Underwood ammo in my G20SF. I see the same small dents on about 20% of my cases and occasionally I get a few cases that look like your last picture. I consider it all normal and I don't worry about it. I don't see anything abnormal when I clean my pistol and I don't have any malfunctions. I don't claim to be an expert on Glocks, I just keep mine cleaned and loaded and it keeps on firing away with no problems.

[novasquid]

I was wondering, can anyone explain what might be causing the dent in the casings?

[zippyhuntin]

The brass is hitting the slide during ejection.

[kylet]

Hitting the slide on ejection is my bet as well.

That or the rounds could be hitting the underside of the slide when inserting a loaded mag... Depending on how aggressive you are at putting in a mag.

[novasquid]

would the stiffer 21lb recoil spring be causing the casing to hit the slide on ejection? what else could be causing it?

my concern is whether or not these casings can be reloaded or if the dent means they should be tossed.

[zippyhuntin]

You can run some rounds with factory spring to see if it disappears. Reloading those rounds is a non issue. The same dents show up on my xd40sc and my 1911. They'll smooth out when you resize.