Quote Originally Posted by Texas10 View Post
If you're experiencing peening of the cartridge case mouth, did you try increasing the amount of tumbling media, or decreasing the number of cases? As you load and start tumbling your cases, media moves into the cases and is not available to cushion the cases from banging into each other. The secrete is to find the best balance of water, media or size of media, cases AND tumbling time. Sometimes less is more when it comes to tumbling time.

As for the burr problem that cropped up, sounds like you have a very tight "no neck turn" chamber. Like you, I anneal and go through the whole clean, trim, chamfer cycle about every third time for my 6BR.

For my bolt action 223's, I only neck size and never get more than a slightly snug chambering round. Almost never trim, or anneal, and still shoot sub half minute groups, but I'm not a competition marksman.
You are correct, this rifle must have a tight neck. I'm not a competition shooter, just a varmint shooter who does not like to miss. Small targets at 500 yards. My other 223 shoots 1/2 inch groups at 200 yards. I think that is 1/4 MOA. I just finished pillar and glass bedding the action on the #2 rifle today in a new Boyd's Pro-Varmint stock so after it sets up for a couple of days I'm going to head to the range with more test loads. I'm looking for bug holes.

I have Lapua brass and a separate Redding FL neck sizing die set up for it and Starline brass with it's own Redding die. Both only bump the shoulders 0.0015. This issue with the peened necks was a new one for me so I thought I would share it. If nothing else I hope that reloaders will learn to try a new round in the chamber before they load up a 100 of newly sized cases. I know I sure will.