Thread: tight closing the bolt

Originally Posted by Bill999

I found that out the hard way mate but its great to have it confirmed
I was necking up to 30 cal after that then back down to 7mm but it wasnt enough only about 3 out of 30 blew primers but the first was mild and the third was frightening. Highly unrecommended that's for sure

I've found that forming the so-called "false shoulder" by going up just one calibre has never been sufficient. Grandpamac's use of 35-cal for .280 would do the job, though the brass in the necks is going to get a good work-out, perhaps 8mm might be a good compromise. My experience has also been to NOT anneal prior to the fireforming and so soften the false shoulder — leave it at as hard a temper as possible, and hope that the necks and shoulders survive being taken up in diameter, back down, and then finally fireformed. But then anneal immediate after the fireforming is done and before asking any more of the neck brass.