I only do it for a couple of my most accurate rifles with small capacity cases such as a 22 Hornet and a 221 Fireball.
If you’re gonna do it you have to make sure you’ve got a good reference for the cutter. Mine is a Lyman and it has a cone shaped, length stop. With it, I do it right after trimming to uniform length. That way I have the cone bearing on a 90 degree edge on the inside of the case mouth as a reference.
I uniform one case to set the stop and then mount it the tool on my case prep machine along with in/out chamfer cutters and go to it. It only takes a couple of seconds and I’m not loading for a ground squirrel or PD shoot.
I don’t think that it makes enough difference but it makes me think I’ve eliminated all variables on the little ones
. Example of one…I did a test with one of my 308 40-XBs. I uniformed the flash holes of 5, uniformed the primer pocket of 5, uniformed both flash holes and primer pockets on 5 and five I loaded with no modification.
I marked each batch but for whatever reason, it was a while before I fired them so it was sorta like a “blind test”. The winning group (200 yds) was one with the “stock” brass. 😳 oh well….
