45-70 Case Resizing

[220]

I am another who has only ever lost 45/70 cases to case mouth splits and even then it always after at least 10 reloads.
I think the thing that extends case life the most is minimising case mouth flaring to the minimum you can get away with.

I think the benefits of neck sizing are greatly over stated and much prefer the security of knowing my rounds will chamber and cycle 100%.
Even with bottle neck cases the majority of failures I see are neck splits, unless you are using collet neck dies or bushing dies neck sizing works them just as hard. I full length size everything apart from the few calibres I have collet dies for.

[Ojaileveraction]

even with bottle neck cases the majority of failures I see are neck splits, unless you are using collet neck dies or bushing dies neck sizing works them just as hard. I full length size everything apart from the few calibres I have collet dies for.

Straight wall caliber dies don't use an expander ball. Is that the same as you are talking about. Collet or bushing?

[220]

[Straight wall caliber dies don't use an expander ball. Is that the same as you are talking about. Collet or bushing?

Yep exactly the same, collet dies use a mandrel the neck is sized around. Bushing dies interchangeable neck bushing in the die, neck thickness has to be consistent to get consistent tension, so really you need to be neck turning or at least skimming them to get them uniform.
I think most of the neck hardening and stretching in bottle neck cases is due to the expander ball being dragged back trough the neck.