Full length or neck size?

[Randy99CL]

Getting ready to order some resizing (bushing) dies for my bolt guns.

I've read that if you get the neck (only) sizing die you will still have to full length resize the cases after 3-4 loadings. So you'll need both dies.
Is ammo more accurate when it's only been neck sized?

Or the idea I like is to only buy the full-length die and just bump the shoulder .001" or so when you resize.

Are there any advantages of one way over the other? Do the cases last longer when only neck sized or does it make a difference at all?

This whole "precision" loading thing is new to me. Used to just buy a standard RCBS die set and go to town.

[Chev2500]

for gas gun i bump the shoulder .003" if it is a bolt .002"
Some still neck size only but the long range precision shooters almost all bump the shoulders

[s3silver]

Lots of different answers to your questions due to personal preferences. I've read most precision shooters full length size now for consistency of brass sizing. I necked sized only before for my 284 Win, but just full length size now. I didn't see any major gains neck sizing plus the rounds are so much easier to chamber every time.

The last batch of 6.5 grendel hornady brass lasted at least 10 firings, all full length sized, with annealing between 3-4 firings. That was for the AR with consistent less than moa groups.

[Londerko]

[Klem]

Randy,

Precision bolt gun shooters can get away with only neck-sizing brass because the compound leverage of a bolt handle being closed on a round is much stronger than the energy of a BCG being closed by a recoil spring. Neck-sizing is better than full-sizing for two reasons;
1. It's more accurate
2. Less wear on the case...it last longer.

Neck sizing is more accurate than full-sizing because the body of the case is still fire-formed to the shape of the chamber and so the bullet is held absolutely concentric to the bore. Some precision shooters even partial-neck-size which means only half the length of the neck is sized leaving the other half to ensure a fire-formed fit in the chamber. Partial-neck-sizing is not without its own potential problems however because there is less bearing surface holding the bullet and that means less neck tension.

As for the advantage of case life...The less you work the case the longer it lasts.

You need full-length sizing in an auto loader to prevent stoppages. You can't get around this. Gas gun shooters size their cases to the bare minimum to ensure reliable cycling and the consensus is .003" of full-sizing. Bolt gun shooters can be anywhere down to .001" of neck-sizing.

If you use the same brass in more than one gun then you have to size to the tightest chamber to ensure they work in all the guns. Or you can keep the brass separate.

As for 'bumping' the cases every 4 or 5 shots. I would hold off on this and experiment as to how long your brass is able to be loaded and cycle reliably without doing this first. You may find you never have to bump the shoulders. I used to shoot F-Class and never needed it. I would discard the brass before it needed it to be bumped (if it ever needed to be bumped). The only time I have ever needed to bump neck-sized cases was a .338L in a Rem700-X long action. I needed to do that every time. I imagine the hotter your loads the more likely you will need to bump them every few firings.