Neck Sizing 101

[RGFIXIT]

Full length sizing works the entire case. When compressed in the sizing die, the case is returned to standard industry specs. These  are based primarily on military firearms and are set to insure consistant feeding. In other words...sloppy as heck.

These sloppy (by our standards) bullets have way too much room to wobble around in the chamber and inhibit accuracy. The bullet isn't starting down the barrel straight and will spin out of round.  This causes less consistant velocities and erratic flight.

Continually reforming the entire case  causes it to stretch. You have to trim the case length each time you reload. Cases wear out faster.

 Neck sizing uses your already "fire formed" cases. When you fire a cartridge in your gun, the case is expanded to the exact size of the chamber and as a result is more in line with the barrel. It is more accurate.

Rather than resizing the entire case only the neck is reduced to hold the bullet. The picture below shows one of my 25-06 rounds. The blue line is as far as the neck was sized.


Well that's sizing 101, hope it helps

Keep your powder dry
RG

[PA_BOWHUNTER]

RG, what dies do you need to do this?  Or are you useing the full length die and not compressing fully?

[RGFIXIT]

PA,
 While you can neck size with a full length die, it's easier and more consistant to use a neck die specifically designed for the purpose.

RCBS is my choice.

RG

[PA_BOWHUNTER]

Thanks RG!  Sounds like a much better way to work up a custom load for your rifle by not only keeping case dimensions consistant but matching your chamber exactly.  In the process extending case life while increasing accuracy, sounds like a win/win process to me.

[RGFIXIT]

You Betcha
RG