Thanks for taking the time to post the info. I will pick up the stuff in hopes that I won't have to use it but will have it if I need to. The bullets that seats deeper than normal is where my signs of high pressure are coming from in the testing phase although I cannot detect the donut, it is the longer bullets that are giving first signs of higher pressures so either my neck tension is too high or I am developing a slight donut. The good news is that the majority of the bullets don't run that far back into the neck.I was thinking that shouldn't have been an issue since I am not turning the necks that may cause the donuts to form but I think there is something going on with crush fitting the standard case and fire forming phase so thank you for the info. Just because I did not detect it on the couple of random cases I grabbed to pin gage, doesn't mean that a select few in the lot didn't develop a donut.I know they were forming on the outside ,maybe when I seating the die deeper it is pushing the donut to the inside ? The necks are not growing in length, partly due the Ackley improved shoulder but with the amount of firings on some of the cases, they should be stretching. I think with the new brass I will not trim prior to fire forming and then hope for a longer uniform case trim length for the reformed brass.Originally Posted by BillPa
One of two things come to mind, extremely hard brass or doughnuts.
This is a dognut
A little ridge of brass that forms inside at the neck-shoulder junction and if bad enough will prevent the expander button pulling through it.
If I suspect the little buggers are forming I use a pin gauge to detect them but you can feel them with straightened paper clip slid down the inside of the neck, you'll feel a bump as it passes the neck into the shoulder. Of course it they're pronounced enough you can also see them with a eyeball.
To remove them I'll push them to the outside with a mandrel then neck turn just barely nicking the shoulder to cut away the thicker brass. K&M makes a turning mandrel with a reamer to cut them out.
http://www.kmshooting.com/catalog/pi...388695985.html
By the same token, if you neck size with a bushing or Lee Collet die ( no expander) and the base of the bullets are seated out past the junction they're not a problem. If a bullet is seated in them when the round is chambered it can restrict the release of the bullet then bad things can happen. This is one result of an undetected doughnut.
If its simply work hardened brass annealing will fix it.
Bill
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