Thread: What happens to factory brass on first firing ?

Originally Posted by ebf

@Cigar, was that "Practical Reloading Manual" ?

Yep, couple of bits in the section on load development about measuring web expansion...
"All cases expand noticeably in the base area on firing whether with factory loads or handloads, so this technique cannot be used on the initial firing".
"After initial case-head expansion takes place, which is normal and does not necessarily indicate high chamber pressures, it's advisable to see that case-head do not increase their dimensions after repeated firings".