I assume that I need a separate die for just neck sizing, then...
Actually... no... you can neck size with full-length resizing dies. Merely back the full-length resizing die back (out) until in just resizes MOST (but not quite "all") of the cartridge's neck. This won't full-length resize the whole cartridge case... it will only resize most of the neck which will enable the neck to hold the bullet securely.
As long as you're shooting the brass in the
SAME,
bolt-action or the
SAME single shot rifle in which it was fired before, neck sizing is all you need to do... and this will help preserve your brass and give you longer brass life because you're "working" the brass less. Doing so also tends to give you added accuracy.
However, if you have two different rifles in the same caliber, you should keep their brass separate and reuse the same brass in the same rifle rather than "mix" the brass and shoot it indiscrimenately in either rifle.
However, if you're reloading for a lever-action, pump-action or semi-auto rifle, then you
MUST full-length resize because none of these actions have the powerful "cam-ing" action of the bolt-action rifles and a case that is not full-length resized may "stick" or hang-up in the rifle's chamber... or not allow the action to be closed on a reloaded cartridge.
Of course, you can also buy a new neck-sizing die, but... again... the regular full-length resizing die works just fine when used to neck-size only in bolt-action rifles.
In single shot rifles, you must be a lot more careful in setting the height of the resizing die. If you leave any "bulge" in the case's neck due to resizing it LESS than down to the beginning of the shoulder, then you will have to PUSH the cartridge into the single shot's chamber that last tiny bit of length due to the neck being not resized just above where the shoulder begins.
Reloading rounds for a single shot rifle is one place where it might be better to order a new neck-sizing only die rather than attempting to use a full-length resizing die backed off to neck-size only. However, you
CAN use the full-length resizing die
IF you are very,
very careful in setting up the full-length resizing die up so that it EXACTLY resizes the
whole neck all the way down to the shoulder, but not quite touching the shoulder itself.
Trim the case
AFTER it is resized (either full-length or neck sized). After trimming, don't forget to chamfer the inside and outside of the case's mouth to eliminate the slight extended "edge" created when the case mouth is trimmed.
The idea in chamfering the case-mouth is
NOT to sharpen it's edge of the case-mouth, but rather to simply eliminate the slight "edge" created when the case-mouth is trimmed.
Once the above operations are accomplished, THEN measure the case to insure it is within "specs".
One of the primary purposes in trimming the case is to insure that ALL cases are the same length which helps to release the bullet during fired at the same point thus enhancing accuracy.
Neck-sizing also supposedly enhances accuracy since the cartridge case already perfectly fits the rifle's chamber and none of the powder's energy is "used up" in flattening the cartridge case against the inside of the rifle's chamber since you didn't resize the case's walls, but only the case's neck.
The only rifle I full-length resize the cartridge case for is my Savage Model 99 lever-action rifle. For the rest of my center-fire rifles (all bolt-actions or single-shots), I only neck-size. I've been doing it that way for almost a half century and it works for me.
ALL of my center-fire rifles,
including the Model 99, shoot 3-shot groups, using my handloads, of
less than a minute of angle (less than 1" at 100 yards)... some
MUCH LESS than a minute-of-angle!~!~!
No brag, just fact.
Strength & Honor...
Ron T.
