Thread: Ring/groove at base of case shoulder

No

Never seen this ��

some ideas to try.. from a contact I'm very lucky to know.
If you're neck sizing it might be a sharp edge on your collet / not enough lube. Maybe a lube build up. Barrel might need a borescope to look for a carbon ring or somethin. Are you gas annealing?

Originally Posted by 6x47

Bit of a mystery. So you're certain this wasn't there from the first fired cases?

The answer is No......no you're not certain, or no it wasn't there on a first fired case.
@grandpamac pointed out a fault with the die too.

So two things to eliminate.....change your die and check your chamber with a bore scope. It could be a chamber fault from a damaged reamer.

In the first post the cases were going to be trimmed. If they are too long is it possible that with the die you are using that the necks cannot lengthen as the case is re-sized, that they are somehow held or stopped ?
PS never had this with a 270 !

Yeet it, clean dies, start over

Sorry...held up with planes and travel.

No not certain it wasn't there in first reloads. Will shoot fresh round tomorrow.

Cleaned dies, checked shoulder bump, blacked out case to see die working.

Put new brass thru FL 6 times and photo beside new not FL sized suggest dies are OK. Bugger that was easiest solution.

Checked box of empties and sure enough there is a short case. I was firing to finish some loaded rounds off without much attention to ejected rounds. Rounds still chamber so I guess this happened after the case ejected.

Hopefully fired new brass tells story tomorrow. Or then go-no go gage.



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New case run thru FL die 6x on right. I know the die isn't having to work the brass as much but sized fired brass show 2 thou bump so not squashing it.



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This is how the experts do it, whatever it is

LOL yeah got some of those. Possibly brass was left to get too long...and putting a crimp in it. Makes sense.

Just fired factory case. It is the rifle.



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Bugger !

That makes more sense now
What is the gun/barrel?

Kimber Montana.

Get the chamber repolished.