Thread: headspace in a break open rifle

So.... GPM asking questions re 6.5x55mm got my brain chewing things over..that and 60 cases waiting for powder n projectiles to be put into them.
my mind was wondering how/where a fella will see fatigue on a case that is repeatedly fired in a break open rifle.
in a normal bolt/lever/pump rifle we see thinning at the web area..its not supported in any of these actions,so the case has a tiny area where it can expand outwards..but in a break open the case walls are completely enclosed so it can only increase in length... making sence so far???
some time back @akaroa1 was testing a lovely 30/30 in same action and fired same case 10 of so times...it was still good...so MAYBE this is the reason???? the case isnt getting the same fatigue????
yes in theory a rimmed case like 30/30 or 303 doesnt have headspace as such..its rim thickness..but we have learnt over the years that resizing these as little as possible so the body/shoulder such as there is ,dont grow much on sizing.
now Im talking 222remington but its same deal really....
also what will pressure signs be??? flattened primer for sure....no swipe mark,no ejector hole to flow into...
thoughts???

also according to manuals it looks like win748 is hands down the best powder for my 16" barrel....even dropping 50fps per inch it looks to be as good as any ADI powder in longer barrel