“it can stretch a lot, and return to dimensions that can mask a problem- for a bit, anyway...”
Not fair, I chamber a round, pull the trigger, then bang, I eject a case that has absolutely no memory of what it was before I pulled the trigger. I have 257 Roberts cases with 30/06 head stamps, 8mm57 with 30/06 head stamps, 243 Winchester cases with 308 W head stamps, I even have 30 Gibbs cases with 30/06 head stamps. I have 30/06 fired cases with 280 Remington head stamps.
My firing pins are mechanically operated, all of my firing pins are driven forward by a spring, again, not fair, I pull the trigger, the shoulder of (some) my fired case never make it to the shoulder of the chamber until the pressure inside the case erases the shoulder of the case meaning some of my shoulders on some of my fired cases never get to the shoulder of the chamber, not fair, time is a factor.
“The fact that the brass didn't blow up doesn't mean excessive headspace doesn't exist- get a no go gauge. Brass is very forgiving- “
‘OR’ become a reloader, get a press, die and shell holder and the companion tool to the press “THE FEELER GAGE’: STUDY the mechanical advantage of the “INCLINE PLAIN’, Again, I have long chambers, I have short chambers, I do not use go-gages, I do not use no go-gages, I do not use field reject gages (I did not say I do not have chamber length gages, I said I do not use or need chamber length gages), because! I have a press, die and shell holders for everything I load for, and I have the companion tool to the press, the feeler gage.
30/06 chamber length gages? I have 280 Remington cases, lots of them, I have a 30/06 forming die, the shoulder on the 280 Remington case is ahead of the 30/06 shoulder .051”, the 280 case will not chamber in a 30/06 chamber, with the forming die I can form the shoulder on the 280 case .051” back to 30/06 dimensions by mindlessly raising the ram, or I can THINK, I can adjust the die off the shell holder and form the shoulder anywhere between .000” to .051” by erasing the shoulder and forming it where I want it. Where I want ‘it’? Again, I have and use the companion tool to the press, the feeler gage.
A reloader can off set the length of the chamber with the length of the case from the usual places, Again, I have an Enfield M1917, the length of the chamber from the bolt face to the shoulder of the chamber is .016” longer than the perfect go-gage length 30/06 chamber. Not fair, because I am a reloader with an adjustable die and press I do not insist on chambering minimum length/full length sized cases in the M1917 chamber, I do not fire to form, I form to fire. forming a 280 Remington case to chamber in the 30/06 LONG chamber is a matter of adding .014” to the length of the case from the head of the case to its shoulder by forming the 280 Remington case, I know, it sounds complicated, I erase the 280 Remington shoulder, part of the 280 Remington shoulder becomes part of the neck, part of the case body becomes part of the shoulder, I would ‘BUMP’ the shoulder but , back erasing the 280 Remington shoulder, by .037” comes closer to being described as wreck when compared to bump, I do not know when bump? starts and erase begins, seems there would be a fine line between case body support and no case body support. I am the fan of case body support.
I have rifles that are different than the rifles used by reloaders on this forum, I know, most do not believe that is fair, I am the fan of preventing case travel, knowing the length of the chamber allows me to form sizes to off set the length of the chamber.