fl resizing vs neck sizing

brickmaster1248

is it necessary to fl resize your brass every time after it has been
from the same rifle or would just a neck size be necesary.

ww2buff9067

Semi-auto, full length, bolt action, no. You could experience feeding problems with a semi-auto if you don't full length size the cases.

Hope this helps,

Mike

jonk

Ditto. Bolt action, neck sizing only is not only fine but probably a tad more accurate.

Lee's neck dies (collet) are great, but any die can be used to neck size only- just back it off the shellholder a turn or two.

joes

Is it true what Jonk said- backing off the dies one or two turns will neck size only? Joe

JustC

setting FL dies to Partial Full Length size takes some work,..and some specific tools. You need a good headspace tool to tell whEn the shoulder has been drawn fwd by .001"-.002". only AT THIS POINT HAVE YOU PFL SIZED THE CASE. Without the tool,..you are just guessing.

You can back the die off to neck size,...and you are fine. I would however reccomend a neck die rather that trying to accomplish the same thing with a die not designed for the task.

I have set most of my FL dies to Partial Full Length size my cases,..since a full sizing overworks the brass. FL sizing is best reserved for a semi-auto,...bolt guns like a PFL or NK sizing for accuracy work.

coledigger4

How far would you back off FL dies to neck size only? When doing NS only, would a person need to trim all of the cases to the exact same length even though all of the cases were fired in the same rifle? Sorry for the hi-jack.

JustC

your FL die starts off a "nickle" thickness from contacting the shell holder. You then use a headspace guage to measure the shoulder length from the casehead. Once you advane the die down,...little by little, until the shoulder gets pulled fwd by .001"-.002", you have PFL'd the case. The body of the case has just been sqeezed enough to cause the shoulder to move fwd, and not touch the die body shoulder. The increased length makes for a good chamber fit which alignes the bullet more concentric to the bore. That equates to better accuracy.

coledigger4

Thank you JustC, that makes sense. I will give it a try. If I am reading this right, the cartridge OAL would have little affect since it sounds like only the body is being 'manipulated'.

JustC

correct,..you have sized the neck, pulled the shoulder fwd by .001"-.002", and have not yet overworked the "expansion ring" just fwd of the casehead. The brass is less dia than a saami chamber dia,..and the brass expands in dia during firing. The squeezing down, and then blowing out of this portion of the case over time, is what causes case-head seperations. By not overworking that area,..your brass will last much longer. Also,..the shoulder of the case centering the case in the chamber by being held "in compression" makes for better accuracy.