Rough chamber?

[FrogFire7]

Should my brass look like this after firing? Score lines all the way around shoulder for entire length of shoulder, spiral lines on case body.

22 Creedmoor, I'm getting this with H4350 just under 39 grains, about 3230 fps. Extraction is very difficult with some swipe... No ejector marks, primers look ok (I know that primers aren't a great pressure indicator). I really dont think this should be a hot load, but they come out of the chamber HARD.

Thoughts?

 

[VinceMule]

It looks like the reamer picked up a chip in the body area. As you can see, the reamer was retracted from the barrel with the barrel still spinning, which is NOT GOOD! Also, the area in the neck and shoulder loads up the reamer with chips, and the chips scored the shoulder real bad. There were so many chips in the chamber that the chips were trying to do the cutting.

Most probably cause was the reamer was not retracted frequently enough, cleaning the chips out of the chamber, and off the reamer. The type and quantity of Cutting fluid used is another issue. Some cutting fluids will not allow a chip to weld to the reamer flute. I am sure that shallower cuts, in the beginning, looked horrible also, if anyone was looking.

That shoulder is the worst I have ever seen on a chambering job.

Everyone has a bad day. Send the gunsmith these pictures and see what he says, I think that he was having a very bad day. His day will get even worse when he sees that brass. The chamber should have been looked at with a AA flashlight at a minimum or better yet a borescope before the barrel was taken out of the lathe..

 

[FrogFire7]

Thank you for the input. That's basically what I suspected...

Am I on the right track with my train of thought as to why it is extracting so hard? I'm a somewhat experienced handloader and this situation is pretty new to me. I'm just not seeing pressure signs otherwise on the brass. I figure if the brass is gripping the chamber hard enough, there naturally would be some swipe as the bolt turns on the case head...

 

[Ucsdryder]

If you say it was from Oregon mountain rifles I might spit my soda all over my phone. I had the same issue, along with a buddy and another guy on here. The rough chamber is causing the hard ejection issues. I took mine to a competent gunsmith and he was able to hand ream the chamber and smooth it out. It's much better now.

 

[VinceMule]

You would have to extend the chamber .003-.005 at least to clean up that mess in the shoulder, which would make your headspace too long with the OP's situation. Then you have to take a corresponding amount off the shoulder, otherwise, you would have headspace too long.

Each situation would be different, and cleaning up the shoulder with 320 grit may suffice, no way to really know.

I would not mention the gunsmith or the company's name until you have given them a chance to fix the problem, in all fairness.

 

[FrogFire7]

Yeah, I didn't plan to throw them under the bus. Always give people the benefit of the doubt

 

[Rflshootr]

I'd throw them under the bus for letting something that obvious out of the shop.

 

[ntsqd]

It may have been a bad day and his/their normal procedures that would have exposed this weren't followed. I'd hold off throwing them under the bus until after you see how they react to this news.

 

[skipglo]

I'd throw them under the bus for letting something that obvious out of the shop.

I'm thinking.....in front of a train....fella might be thin enough that the bus passes right over him without a mark!
...

 

[big johnson]

If the gun was test fired before you got it the gunsmith should have saw it ,but someone else in the shop might have test fired the rifle and said it was ok. Give the smith the chance to make it good . I would like to hear what you find out.

 

[KS2506]

You could get a smith to clean up the chamber, and if a small amount longer, neck size the brass.

 

[spladi]

Should my brass look like this after firing? Score lines all the way around shoulder for entire length of shoulder, spiral lines on case body.

22 Creedmoor, I'm getting this with H4350 just under 39 grains, about 3230 fps. Extraction is very difficult with some swipe... No ejector marks, primers look ok (I know that primers aren't a great pressure indicator). I really dont think this should be a hot load, but they come out of the chamber HARD.

Thoughts?

I think you are way over pressure, tend to that issue then inspect your brass.

 

[charles bonner]

That chamber is terrible. They will need to set it back one thread and recut the shoulder then rechamber it. Pressure has nothing to do with it until you have a smooth surface chamber. Then you can work up a load.

 

[FrogFire7]

I think you are way over pressure, tend to that issue then inspect your brass.

I appreciate the thought, but should be well under max with my powder charge. I just tried 38 grains again with the same issue. Attached pic of case head.

I spoke with the barrel smith, he was very willing to take it back and clean it up. Offered some other suggestions as well to try.