I sized some 300 WM brass bumping the shoulder back 0.003". Tried chambering the brass and it was fine.

Needed to trim the brass as it was long, so trimmed to the noted 2.610". Chamfered and deburred the brass.

Now, I'm having problems with the bolt closing. I thought it was a slight edge on the outside of the case mouth due to improper deburring, so I really put a deep outside deburr on about a half dozen brass. It seems to be better, but still a little resistance when trying to swing the bolt handle down on some of the brass I worked over.

If you remove the brass and turn it slightly, sometimes it helps, sometimes not. Other times, it closes without resistance.

Any thoughts on what might be going on here?

Thanks,

Does the shoulder still measure -.003

quote:

Originally posted by ted thorn:
Does the shoulder still measure -.003

Yep, same measurement before and after.

Yet, an unsized, only cleaned case will chamber, which is + 0.003.

Now that's a real mind bender. I'd sure like to see the whole operation. roger

I'd say you have made it out of round.

The fact that sometimes turning the brass helps
kind of shows this.

I would resize again.

quote:

I'd say you have made it out of round.

I'm with 505G on this topic.

I think you may perhaps be concentrating on the wrong end of the case.

You've already trimmed so it's not case length, and chamfering is now O.K., too. Regarding the mouth of the case you could be bulging the case mouth or neck while seating the bullet. That should pretty much cover potential issues at this end of the case.

As for the case base; could be a number of issues; chamber out-of-round, Dies the same or the belt.

either out of round or perhaps in the whole trim and chamfer process you expanded the neck somehow

What kind of case trimmer do you use?

Well, I think the problem has been solved.

There was a slight shim of brass on the bolt face up against the extractor. How it got there, who knows. But, it was large enough that it could have been causing the problem.

Also, there was a notable difference between hand feeding and running the case thru the magazine when chambering.

Yep, it is a CRF rifle.

quote:

Originally posted by Pegleg:
What kind of case trimmer do you use?

RCBS trim mate

Graybird,
You answered your own question before I got to it. Had the same thing happen to me and it sure was a head-scratcher. Finally found the little piece stuck to the bolt face and everything was fine. Live and learn.

Well, the darnedest things that come out here!