For purposes of getting a clean release from the shell it's probably better, but for purposes of precise neck tension I would say if you don't have a generous neck it could be problematic.Something mentioned above in this thread triggered a thought. The idea stated was that a mandrel will push any thick neck sections to the outside. Logical and reasonable that this is true.
The thought that I had is, is that good? Not that having an inconsistency on the neck ID is good, just that having an inconsistency on the neck OD means that the bullet may not be centered in the throat of the barrel. That would be bad, too. I know that is part of what neck turning is all about. to make the neck as uniform in thickness as possible.. It was just that the statement didn't seem to account for, or acknowledge that.
What caliber? I've started really buying into initially running smaller calibers tighter and larger ones looser.I use .002 mandrels and undersize .001-.002. . I tend to see similar SD and accuracy with a little more tension, .002-.004, so I'd tend to just stick with it. I've played with .001 tension and struggle to get consistency there without turning necks.
I have had similar problems with reloading Hornady factory brass. In my opinion, all these necks need neck turning.What caliber? I've started really buying into initially running smaller calibers tighter and larger ones looser.
After going over a lot of info from Mike and Mark and other smart guys something I messed with is shortening the length of neck sized on my .338 while using the same sizing mandrel to open back up has shifted the groups some. Not turning the necks and using a full caliber mandrel (LE Wilson "new", I think it's actually .338 - to try to target .0015 spring back on new brass), so pretty loose.
Hornady factory loaded brass, not very well matched, could be case volume causing differences also.
I've learned after a lot of trial and error and generally being headed that neck turning should simply be a part of our normal bras prep with new brass or once fired brass from factory ammo.I have had similar problems with reloading Hornady factory brass. In my opinion, all these necks need neck turning.
I'm not comfortably myself with so little neck tension especially one that is magazine fed.I can see how there are so many things that work for everyone in a different way, but man it is frustrating!!
So if I anneal every firing with an AMP mark2, then I would assume the spring back is very little compared to brass that's been fired/sized a few times. At least that's my experience in a few different cartridges when using standard FL sizing dies. So that said, I'm assuming. 003-.004 down with the sac bushings and up to .002 under bullet diameter with mandrels? Would assume if I was .001 under I'd not have enough tension with annealed brass?
I appreciate all the info guys.
204, 224, 6mm, 6.5. Haven't tested much on the 30's. Don't really shoot them anymore. I never felt the 30's were that sensitive tho. I just run a .002 mandrel on everything now and it seems to work fine. I'm not a bench shooter tho so maybe my acceptable accuracy is less than others. If I can get .5moa consistency with low sd I'm happy. I don't intentionally chase bugholes AT ALL COST anymore. I look for it but I'll stop once I get a solid performer.What caliber? I've started really buying into initially running smaller calibers tighter and larger ones looser.
After going over a lot of info from Mike and Mark and other smart guys something I messed with is shortening the length of neck sized on my .338 while using the same sizing mandrel to open back up has shifted the groups some. Not turning the necks and using a full caliber mandrel (LE Wilson "new", I think it's actually .338 - to try to target .0015 spring back on new brass), so pretty loose.
Hornady factory loaded brass, not very well matched, could be case volume causing differences also.