Full length or neck sizing on straight wall rifle cartridges? Stuffs not cheap, not sure how much full length sizing may reduce life. Already have full length dies, not the neck dies
I guess you could size for neck tension only, if the fired shells will chamber. I don't think FL sizing would really work the brass too bad on a straight-walled case - maybe experiment, and see if one lasts longer than the other.
only time I'd neck size is for a specific bolt action rifle, and then you still have to full size every few firings because the case will be too tight to fit the chamber smoothly. Definitely extends brass life over FL sizing with a necked case, but if you're going for long range precision you'll probably still want to FL size to minimize any variations from one case to the next.
Single shot you're better off resizing enough to chamber & keep headspace as close to neutral as possible . Just screw your FL die in the press far enough that a resized case will chamber easily ie partial resize & if that gives enough neck pull you're golden .
You don't need elephant loads around here for anything with the .45-70. That big hunk of lead tooling along at moderate speed will dispatch anything we have that needs dispatchin. Save some powder and take it easier on your brass.
.45-70 is a rimmed cartridge...it uses the rim for headspace. As long as the case is trimmed properly there shouldn't be any issues created by headspace like you would find in a bottleneck case.
One of the first failures on a bottleneck is, is the neck or primer pocket from hot loads. Annealing the case will return it to a softer state after work hardening occurs.