I would say that's it in a nutshell

I can add a bit into this as most do not have that experience.

I am into US Mil surplus guns, mostly Model of 1917s (30-06 - WWI era )

That gun normally goes to the limit on what is technically called Field Reject Gauge.

Shooting those guns and the brass stretch first shot is a zero issue. Reloading them then to work in a a modern gun is.

I segregated the brass for those into their own special group. Once its fired formed it stays that way with the normal minimum shoulder bump back (a bit more, this stuff is sacrificial to a degree as any range brass that is clean and once fired is good fodder for them). Fire formed to those chambers and once it is as long as you don't try to make it fit a modern gun the brass does fine.


Where it would play out to bad would be if I shoved the shoulder all the ay back so I could shoot it in my 111. Then it would crack at the base quite soon.

This is an extreme example, but keep in mind they could have cared spit less about SAMMI, what they cared about was keeping those guns shooting in the mud, the blood, the muck and no beer.

The bottom line is you want all your common chambers set the same, segregated the brass or you will get case cracking well before the brass has used up its life.

I too have the set of gauges, if you want to make a field reject, then a no go gauge with freezer tape on the back will do it.

Go gauge with thin tape on the back makes it a no go.

And after working with it, I am just setting it so that the bolt begins to close on the Go gauge, and that is good enough.

The brass is shot in two chambers and they are both so close that the minimal bump back works fine.