Thread: Case lengthening when bump sizing

All of these issues can be identified and correct by doing the appropriate measurement.

Originally Posted by -BW-

Perhaps I have misunderstood the opening statements around the problem, but if a full length resized case won’t chamber as stated, then in my opinion it just hasn’t been sized enough.

I don't really agree with this BW. The case may well have been sized correctly, but during that process, brass flowed into the neck causing that to get longer. The shoulder and other case dimensions may well all be within spec.

Couple of suggestions from my side:

If you want to measure sizing in relation to the shoulder (i.e. bump), use the correct size bump gauge to measure the datum line.

To see if you need to trim, measure overall case length AFTER resizing. (@Dermastor) If you don't think cases stretch during resizing, simply measure the case BEFORE and again AFTER. DO multiple measurements, and make sure the flat part of the vernier blade is seated well in the case.