Partial neck sizing

[Jumper]

I normally neck size my .308 cases with a Lee Collet Die and I wanted to try partial neck sizing to see if it improved accuracy. I took some Federal cases and turned the necks a little to clean them up and partial neck sized them with a Redding Type S bushing. I loaded up these cases and and some Federal cases that were full length sized and shot some 3 shot groups at 100yds. I didn't see any improvement in accuracy in the Partially neck sized cases. In fact these cases produced more "flyers" than the Full length resized cases. Has anyone been able to improve their accuracy by partial neck sizing?

 

[USMCj]

Re: Partial neck sizing

you should be partial neck sizing after you have fired the brass in your chamber, not after turning the necks and such.

take those neck turned and fired cases, size only 2/3rds of the neck and see how they do.

 

[MitchAlsup]

Re: Partial neck sizing

Partial neck sizing is worthwile after you have decided one bushing is too tight and the nest bigger one is too loose. Here, you use the tighter bushing but only size part of the neck, in effect attempting to get teh neck tension of a bushign between the two you have on hand.

A partially sized neck is conducive to bullet runout, so be careful here.

 

[Jumper]

Re: Partial neck sizing

Referring to USMCJ's post: Thats what I did. I took the Federal cases, turned the necks enough to clean them up and make them all consistent loaded them and fired them in my gun. I then took these twice fired, neck turned cases and partial neck sized them and used them in the comparison with the FL resized cases. Sorry if this wasn't clear in my original post.

 

[308isgreat]

Re: Partial neck sizing

Yes, sizing only about 2/3 of the neck has improved accuracy in SOME of my rifles. Others I couldn't tell a diffence between sizing the entire next or partial sizing. It made a big ass difference in my PPC (for the better).