Mikecr
Well-Known Member
Is this trimmer non-adjustable? I would think all trimmers are adjustable in some way.So I wouldn't be able to do this with a Lee trimmer, correct?
And cutting to shortest length in a group IS arbitrary.
The common way reloaders cause excess chamber end clearance is to cut all necks (as new) to a shortest in batch length.
Then, when they fire form cases, necks will pull back with shoulder angle increases, leaving even more clearance.
There was never a logical reason to do this.
When you see a lot of soot on fired necks, sometimes further down cases, it's often caused by excess chamber end clearance.
The price for this can be increased SD, as neck sealing then varies in timing. The rearward carbon movement also deposits a carbon ring, which again affects sealing, and can delay bullet release from necks (jacking up pressure peaks).
Ideally, you would measure your chamber length (with a chamber length gauge), and as brass eventually encroaches within 5thou, you would trim to no more than 10thou short. Most cases should get there around the same time, but some may never get there,, or the whole batch may never get there. Just measure & watch it.
While your watching, the price for varying neck lengths(within normal), or case mouths off-square, is nothing provable.
So just let your cases get to where they should be trimmed before doing so.