Shoulder Damage On .308

I have been learning my gun and the right load. I have a Savage 12F/TR I have about 400 rounds through it and found It shoots 42gr of Reloader 15 with 168grMK the best. I have tryed all types of power and primers and a boat load of bullets. You guys have help me find the right seat depth and .010 off the lands seems to be the sweet spot. Here is what happend at the range this weekend I was shooting at 300yd and trying differant loads and I was checking my brass and found some of the older rounds that I reloaded with WIN brass at the edge of the shoulder it had some deep marks in the casesand it was only found on Win brass. I had 20 rounds of Lapua Brass with the same loads and it look fine. Is It something I am doing wrong are bad brass. How is the best way to check the chamber of my gun? Could it be the problem. The Lapua brass was new, but I did full size the brass and trim to spec before reloading. I did use differant dies with the lupua brass I used RCBS COMP DIES. I thought it maybe the dies I was using when I reloaded the Win brass??? If this is a normal thing please tell me..

What kind of marks did you find? Scratches? Dents? You said the marks are at the edge of the shoulder. Do you mean at the shoulder/body junction, or shoulder/neck junction?

Are you sure the marks were not there before firing? Sometimes dents on the neck are caused by too much lube during resizing.

It'd be great if you could post pictures.

Well it was scratches a little deep from the shoulder back tord the body of the case, It was about 5 cases out of 25 that did that??

Scratches ??? ???

I would start by looking for any burrs in the receiver, specially the feed ramp area. Magazine lips sometimes scratch up the cases but your rifle is a single shot, isn't it? See if you can find a burr, something that could be scratching the case as it is pushed by the bolt toward the chamber, or as the case is extracted. Perhaps you can use the tip of your finger to try to feel any burrs. Also it might be good to check the resizing dies to see if there is any dirt or metal shavings lodged in there.

I don't think it is in the dies because the case look great after I finish reloading them and I check the chamber the best I could. The last 20 cases that I reloaded and fired looked fine, Could it be just some bad cases??

It could be during ejection. The extractor plunger puts pressure on the case that forces it against the side wall all the way out of the chamber and along the receiver until it clears. If you have a burr, look for it with your finger along this surface area.

I think it was you who had another post about cracked case necks and had got some brass from someone who said it was once fired from a police range.

As in the other post, if these are some of the same used brass, it's possible the brass was fired from a rifle with a fluted chamber.
Once fired Fluted chamber brass is throw away brass.

John K

Some military automatics have fluted chambers to assist in the gas extraction. If your brass was fired in one of these guns you could see the vertical bulges along the case body. Yes, they are throw aways. RECYCLE I mean.