Neck turning???

[Scott E Ames]

You did not mention if you have resized your once fired brass. If you are bumping the shoulder it is fairly common for the necks to grow a little after resizing. That may push them out to a much closer to spec length. Some trimmers work best after resizing as they index on the shoulder and you will get more consistent overall case length.

 

[Blackhawk]

From my measurements I should only have to take a couple thousands off to true necks. I was worried about trimming length. .005 under trim to length would not be to much?

-.005" under minimum case length will still yield a usable case. In my post above I suggest using a reduced powder load of -5% under maximum.
Before loading examine brass hulls for the obvious signs. If all is well then mark these as reduced loads and shoot them at the range.
Your empty hulls now are fireformed and should have expanded to your chambers dimensions.
FL resize and trim to length as normal.
Problem solved !

 

[smokin_gunn2]

Cases are already once fired and still short .005 after being FL sized shoulder bumped .002. Going to trim and turn some and leave some the way they are. Load enough to shoot groups and take chrono readings to see if there is much difference between the two. I run a wiser mount so I can get readings without poi change.

 

[L.Sherm]

Trim them all to the shortest length within reason, that brush you should be using to clean the carbon ring isnt gonna know the difference if your .005 or .015 shorter than max, trust me it's not gonna hurt a thing.