Modified shell holder
The primer drop thru hole happens to be 5/16" which is the drill diameter for a 3/8-16 thread.
I also counter sunk the bolt end to clear the live primer while being held so the clamping pressure is on the head stamp part only. Also, as you can see I milled 3 flats on the shank for chuck jaws using the hex head
in a vise before I hack sawed it off. The flats aren't necessary, but it was easy enough having a mill to do it with.
I spin rounds wiping them w/ the scotch-brite to make 'em bright before dusting them with Mohawk lacquer
for brass, this keeps 'em showroom shiney for years to come, if your saving them for future hunts.
Now, here's where it gets real interesting . . . . .
Does spinning live ammo like that on a drill effect the powder & performance of the round?
My answer is yes, in a good way! After testing at both 100 & 200 yards compared to Not spun ammo from the same lot (10 rounds vs 10 rounds made as a lot of 20)
I did the test using CFE-223 in .223 & H4895 in .308
Ball powder groups were noticeably smaller (1/4-3/8") while stick powder groups were a little smaller.
The results were the same after testing 3 different times / 3 different lots. I'm very pleased with this.