Hey guys, wasn't sure if this should go here or medium bore forum, guessed here but mods please move if not right.

I have a 308 Norma mag that is going to be my primary gun in Utah in October. I hadn't shot it in years and broke it out the other day, still seems to shoot well

the problem is I've only put about 40 rounds through this thing, same 20 pieces of brass. I don't know if I noticed before or not but last night when resizing/decapping I noticed scratches/marks running parallel to bore line. they don't seem to be worse in any spot (meaning they run from just above the belt to the shoulder, not solid there's interruptions here and there).

My guess is that there is a spot in the chamber, close to where the belt headspaces (not sure the names of parts of a chamber) that has a sharp spot in it.

My question is should this worry me? I want it fixed regardless but if it comes down to me getting it back in time for season is it safe to hunt with like this (have had no trouble shooting it).

Usually I'd ship it off to somebody to have it taken care of, but the local shop that originally did the work on it stands behind things and will probably correct it free. But if sending it away would get it taken care of faster I'd go that route as I still need to develop a load for it before I go so need it in my hands.

Thanks guys.

Red

It's not clear from your description at exactly what point you discovered the scratch marks, but if it was subsequent to resizing then I would be much more suspicions of a problem with your die (imbedded dirt or metal, rough finish, etc.) than with your chamber.

If it is the chamber, my guess, sight unseen, would be from a burr or something at the belt. A little chamber polish should take care of that. You could probably wrap a piece of green Scotch Brite pad around a dowel and clean it up with a hand drill. In and out real fast. Out of the stock of course.

Sorry, I noticed it when I went to size, however I sized 20 pieces new brass prior to sizing the fired brass, no marks on them.

Red

well guys, safe? I talked to local shop they can work on it and have back to me in three weeks, makes things tight so this weekend I'm going to go out and work on loads some then drop it off to them.

Red

Hey guys i got some pictures, it is definitely happening when I chamber the rounds. I took it to the local shop and they said it was normal. I don't know about that, I took my stepdad's 308 norma to the range today and it doesn't do it. Looking at it I'd say the belt counterbore looks like it may not be smooth. Anyways, I can even see brass in the lug raceways after a few cases are through it.

gun shoots great though so if this really isn't unusual, or isn't something to worry about I won't.

quote:

Originally posted by Dago Red:
Hey guys i got some pictures, it is definitely happening when I chamber the rounds. I took it to the local shop and they said it was normal. I don't know about that, I took my stepdad's 308 norma to the range today and it doesn't do it. Looking at it I'd say the belt counterbore looks like it may not be smooth. Anyways, I can even see brass in the lug raceways after a few cases are through it.

gun shoots great though so if this really isn't unusual, or isn't something to worry about I won't.

That looks to me like it is a feeding issue, not a chamber issue.

I would think that marks made by an imperfection in the chamber would only be resulting from extraction & would be much more consistant.

After having a second look, there apears to be marks from possibly the chamber as well as the feed rails.

Maybe some rust spots?

Thoroughly inspect the chamber with a cotton swab. If there are any minor burrs in there the swab will leave fibers behind and it will be easier to see.

then check ever edge the case comes into contact with on it way into the chamber. Take the rifle apart and feel with your fingers any rough spots on the feed rails, or follower.
Could even be to tight of an extractor not allowing the cartridge to seat on the bolt face easy enough and the case is dragging heavy on the action

It's a burr at the forward edge of the belt. If you make it to Utah early enough, run it by and I'll see if I can't knock it out for you.

hey Westpac thats a real kind offer! what part of Utah are you in? I'll be in panguitch all the way till 29th. I'd be real appreciative if I could get you to look at it, at the least have a beer

Red

If the gun has a coned breech in the barrel the edge of the chamber may not have been broken(polished or radiused). This could also be the case with a square breech face. See if it scratches it just going in the chamber. By that I mean don't fully chamber the round, just go in far enough to pop up into the extractor then remove it. If it scratches then it is the leading edge of the chamber most likely.

I LOVE my brass SCRATCHED. It helps me sleep.

quote:

Originally posted by Dago Red:
hey Westpac thats a real kind offer! what part of Utah are you in? I'll be in panguitch all the way till 29th. I'd be real appreciative if I could get you to look at it, at the least have a beer

Red

I'm in Salt Lake City.

If it was a burr in the chamber then you should see consistent scratch marks on all the cases. Since the marks appear to be random I'd suspect a feeding issue. Look for sharp edges on the feed rails.

quote:

Originally posted by clowdis:
If it was a burr in the chamber then you should see consistent scratch marks on all the cases. Since the marks appear to be random I'd suspect a feeding issue. Look for sharp edges on the feed rails.

Look at the pictures. Look at the forward edge of the belts. My money's on the chamber. And, if you look closely at the cases, the scratching is fairly uniform.

Looks just like my .375 until I deburred the belt chamber edge.

quote:

Originally posted by Westpac:

quote:

Originally posted by clowdis:
If it was a burr in the chamber then you should see consistent scratch marks on all the cases. Since the marks appear to be random I'd suspect a feeding issue. Look for sharp edges on the feed rails.

Look at the pictures. Look at the forward edge of the belts. My money's on the chamber. And, if you look closely at the cases, the scratching is fairly uniform.

Well, I certainly would not neglect to chamfer the edge of the belt ring but I'd go through feed system also.

hey Westpac I'm told I'm about four hours away, thanks for the invite but ifnthis Morning is an indicator I'll need every hour to get a deer.

looking at the edge it looks like it needs to be smoothed out, you're seeing right it is scratched worse right at the belt from how I see it AND the case isn't coming fully into the bolt face, extractor may be a bit too tight. I'm guessing a just lightly hit the backside if that extractor to massage that?

is smoothing that edge myself with some cloth and a rod/dowel safe on my own? I just don't wanna mess the chamber or headspacing up

Strange but very consistent pattern to the scratches on the cases. I've looked hard at the the photos and tried to imagine the cases feeding from the mag to the chamber. As they don't rotate I can't see how they would get that sort of pattern from the feed rails or ramp.

Has the mouth of the chamber taken a hit from the cleaning rod, I assume the rifle got a good clean when taken out after such a while of rest. Slightly variation in height on any circumferential burring around the chamber mouth could account for how the pattern of scratches develops as the tapered shell is feed into the chamber.

I have seen scratching from feed ramps and rails but they seem to be in one or two distinct places and are often straight along the case near enough end to end.

quote:

Originally posted by Dago Red:
hey Westpac I'm told I'm about four hours away, thanks for the invite but ifnthis Morning is an indicator I'll need every hour to get a deer.

looking at the edge it looks like it needs to be smoothed out, you're seeing right it is scratched worse right at the belt from how I see it AND the case isn't coming fully into the bolt face, extractor may be a bit too tight. I'm guessing a just lightly hit the backside if that extractor to massage that?

is smoothing that edge myself with some cloth and a rod/dowel safe on my own? I just don't wanna mess the chamber or headspacing up

If you hop on 89 N. towards SLC, this evening, at around 8:00 pm, there is a fair chance you will hit a deer by the time you get to the I-15 junction.

Westpac I should have taken your advice, it would have been my best bet at getting a deer . I'll do a report later.

now that I'm back, is this something I can fix myself guys going slow and taking my time? I need to loosen up the extractor so that it lets the cartridge all the way up on face, and I want to smooth out the chamber, how about a bit of guidance?

Not that I have anything against the local shop, but obviously they missed it the first go around and the guys they used to have I had more confidence in than the current bunch. I already had to take another rifle in there for them to rework the chamber on it for me.

Thanks.

Red

quote:

Originally posted by Dago Red:
Westpac I should have taken your advice, it would have been my best bet at getting a deer . I'll do a report later.

now that I'm back, is this something I can fix myself guys going slow and taking my time? I need to loosen up the extractor so that it lets the cartridge all the way up on face, and I want to smooth out the chamber, how about a bit of guidance?

Not that I have anything against the local shop, but obviously they missed it the first go around and the guys they used to have I had more confidence in than the current bunch. I already had to take another rifle in there for them to rework the chamber on it for me.

Thanks.

Red

The best job will be accomplished by removing the barrel and spinning it in a lathe while polishing the chamber. The extractor work should be a breeze for a competent gunsmith. That's what I would recommend.

Hey Red,
I get exactly the same thing and it has been happening for a long time. As all of my rifles are working rifles, they have a hard life, but these scratches has had no effect in anything I have done and the rifles have performed as they should. Personally, I dont think it is something that you should worry about.
Unless it causes you to lose sleep.

Best Regards
Marius Goosen

My old Ruger .257 Roberts would scratch brass in a similar manner. When a gunsmith opened the chamber up to .257 Roberts 40 degree AI, he turned the barrel back two turns before reaming. He also polished things up and radiused the edges. No more scratches was a nice side effect of the work.

Good choice of caliber, btw.

I do not know if making the rifle into an AI configuration was worth the cost for ballistic improvement, but .257 AI cartridges with a plastic-tipped bullet look way too cool for school.