Back to reloading after many years off and things have changed somewhat due to technology. I recall just looking at primers but now folks are measuring the expansion at the base. I noticed my loads were at .006 and then shot some factory only to see .oo8. Both seem high to me. Is there a rule of thumb out there?

quote:

Is there a rule of thumb out there?

I think the more reliable measurement is primer pocket expansion.

If one can get three reloads and still have sufficient press fit to seat primers then he's good to add more powder.

The problem with case head expansion...(CHE) is that it requires very sophisticated micrometers (mine is over $100) and rigerous attention to where the dimension is taken......but it certainly can be done.

Primer pocket expansion is a much easier and surer thing to monitor!

I work up until the extractor groove expands .001" and back off 6% for a usable load ala Vernon Speer 1956. To detect the threshold of shorter brass life, that measurement is more sensitive, faster, and more replicatable than waiting for a primer to fall out or waiting to see how hard it is to insert the next primer is inserted into that case.

That change can be measured with the resoluion of any $15 dial calipers from China.

http://forums.accuratereloadin...621010501#2621010501

Thks..fyi. Federal replied to me that .008 is an acceptable level....

thanks for the veteran insight..

quote:

Originally posted by garyn:
...folks are measuring the expansion at the base. ... Is there a rule of thumb out there?

Hey Garyn, I use good-old never-fail CHE and PRE to determine what I consider a Safe MAX Pressure. Those Methods have worked well for over a century and will continue to work well into the future.

Best of luck to you.