My answer is "it depends" Neck sizing is great if you are only using your own brass that has been fired out of your rifle but full sizing is good if you are using range brass or semi-autos and want to get it back to factory specs. Neck sizing tends to be a more accurate load.
I think it would depend on the purpose of the ammo also. I would never neck size or partial size hunting loads. If you do then every so often you have to full lenght size to back up the shoulder just a bit so it doesn't get to thight to smoothly close the bolt. With hunting ammo you want ammo that doesn't get sticky because the case has grown just a shade to much.
Everytime you fire the case and reload it, if you neck size, the case grows and then doesn't shrink back down to normal. After a while, several rounds, the case fits the chamber to perfectly and doesn want to go in. You might be able to set the full length die to bump the shoulder back a tad every time but I've never been able to do that. If you do try it, you'll feel the case get to big with the bolt as it get a bit harder to close it. When that happens, look at the bolt face and you'll probally see brass rubbed on it. That's because the case fit's to perfectly and the shoulder needs bumped back.
Is it fair to say then that brass shot from your rifle but full length-sized, not neck-sized, is not really fire-formed brass?
Bingo! As soon as you full length size it, it is back to normal cartridge specs as per the original specs and should work in all rifles of same caliber not just yours. Fire-formed and neck sized catridges will fit your rifle but not always somebody else's.
Thanks, Chester. Is their enough added accuracy to make it worthwhile to only neck-size one's personal brass? I don't shoot a lot and I buy new brass in bulk so I probably one would re-use brass a few times.
Unless you are bench rest shooting I doubt you will need fire-formed brass. Full length sizing will be fine for any hunting or normal target shooting. The ammo (full length ammo) tends to be a bit more reliable feeding and ejecting and if you are using a semi full length is the only way to go.
First make sure your gun is safe, remove the bolt and clean your barrel from the chamber to the end of muzzle. Clean the barrel using butchers bore shine until a patch comes out white. Run a total of 5 separate patches soaked with denatured alcohol through the bore and let dry for 30 minutes. Insert a cleaning rod with a jag and a dry patch into the neck of the chamber. Make sure it will stay there through the next process. Now using another cleaning rod, install a patch that has been coated...