For new brass I partial FL resize then measure the case neck thickness to keep all brass within .002 of each other.
After shooting 24 shots over the weekend, only about half of the new cases are opened up enough to easily slide a bullet in and out of the neck without it catching. This is Winchester brass. Is this normal? Some of the brass only catches a little while others are very tight. How much will those tight necks effect accuracy? Thanks.

Quite a bit! You have to be sure you truly do have a tight neck. It could be that springback in the brass after firing could be misleading you. Measure the necks of your fired brass, then measure the neck of a loaded round. You should have at least .002" difference in the two. If you don't, then you best be considering either another lot of brass or either turning or reaming your necks for clearance.

The different "grip" on the bullets at firing will affect the burn of the propellant and alter pressures if the necks are not reasonably consistent.

Thanks Bob.

Let me duplicate this on this thread, it is more on point than in an equipment discussion


Just got the Lyman Accutrimmer, and outside neck turning accessory. Main reason for this choice is that they include many collets and pilots with the units, and dont want 8 buck for every caliber I need. That is a sales approach I will reward.

I got it working well last night, probably only ruined a couple of well used cases as I practiced. How close to the shoulder transition radius do you cut? And for thinning, rather than just knocking off the thick sections of the neck to make it more uniform, would you make more than one pass taking a little at a time. I might want to take .003 from the wall thickness. Is this a bad idea?