FL vs neck sizing

G

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What are the pros and cons of each? What gives best accuracy, case life, etc.
Thanks
 
Neck sizing tends to give the best accuracy and case life. The only thing you're changing dimensions on is the neck so the case fits snug in the chamber and better aligns with the bore. By annealing the necks regularly you can reload cases for years. I still use cases I have from the 70s. The down side is those cases may only fit the rifle they were shot in and may tend to be a bit snug while chambering. I don't use really hot loads and haven't run into this yet.

Full length resizing is best for using cases in different guns and ensures ease/reliability of chambering. It's best suited for hunting dangerous game, semi automatics, and maybe beginning reloading. Down side is a looser fit in the bore, more work done on the brass (possibly shorter life), and a little less accuracy.


That's all I can think of.
 
It will greatly depend on if you have a tight custom chamber or factory chamber and/or if you run max loads or not. I have a factory rifle and a BR chamber in a custom rifle and prefer FL and neck sizing.

I prefer FL sizing due to cases fitting too tightly in the chamber. Neck sizing isnt bad if your loads are not real close to max loads. If you are using top loads you might get a couple firings before they are too tight. Some custom die makers can make you a FL die based on a fire formed well fitted case that you can use that will give you the best all around results. A round that fits too tight can have just as bad results accuracy wise as too sloppy. If you feel much resistance when loading a round into the chamber, its too tight

Please note that when I FL size my cases, my dies do not toch the necks. I use a neck sizer only to utilize my tuned necks so as to get perfect neck tension. So in a sense I do both, but still prefer my cases to feed smoothly scince I run top loads. In no case do I use an expander ball, which only causes case run out or crooked necks. This is where the neck sizer comes in.
 
What die do you use when FL sizing without touching the neck and what die for neck sizing?
 
I actualy use a standard FL (Lyman) die for my 300 RUM and because my necks are turned down, and I dont get much expansion the neck dosent touch the die. Then I use a Redding "S" series neck sizer. S series allows you to change the bushing inside for differant neck diameters.

You can find a body die that is specifecly made to not touch the neck. I think Wilson makes one and I know Redding makes one. I have seen them in the Scinclair intl. catologue. I hope that helps some.

http://www.sinclairintl.com/cgi-bin/category.cgi?category=search&item=RD75XBDIE1&type=store
 
I use a $24 RCBS full length die set for a couple of calibers because they produce straight ammo. I always buy a RCBS full length set, if for nothing else to straighten out necks of new brass. Sometimes, that is what I continue to use. If the set doesn't produce straight ammo, or I need more neck tension....

"What die do you use when FL sizing without touching the neck and what die for neck sizing? "

I'll get a Redding S bushing neck die and follow it with a Body die. I always full length, (shoulder bump) and never anneal.

IMHO, neck sizing only has merit for the little 100yd bughole shooters but don't do much for 500 and beyond. Not real sure how much straight ammo does for it either, but I still strive for it anyway. Gives me warm fuzzies. I got a 25-06 that would make most of you nauseous if you rolled the cases on a table but the thing sure likes to shoot. It's a Savage, I don't know if the bolt head flops around or what but there are visible lumps on the sides of the case bases. Did spin them on the casemaster once and after the first one rolled about a .007 out of round, I put the casemaster up and decided I really didn't want to know. It doesn't seem to mind and still likes to shoot 2 to 3 inches most of the time at 500.

My brass usually lasts about 7 firings and then I work up a new set for matches/big game. I don't throw the old ones away but transfer them to a bucket marked(Woodchucks)and as I am seating primers, if they go in real easy, I mark the case head with a sharpie and after that firing they go in the trash. I also measure last leg 300wby brass for the case walls thinning. .010 thinner than new is my cut off and they also go in the trash.

One test I did was take two cases, fire, measure everything on each. FL one and neck size one. Measure for case thinning, length, concentricity, etc. By seven rounds with a 300 Wby, both cases had thinned in front of the belt by .009. I know from previous experience .013 is one shot away from case head seperation. The two things the neck size gave me was, slightly less trimming, and harder bolt lift, really bad by the 7th shot.

On the 30-378 I got to 10 times fired FL sized case and got bored with the test. No thinning but primers starting to seat easier.

I may try annealing some time if I ever have a case that isn't spent by 15 firings due to wall thinning or primers loosening. Until then, in a 300 rum, 300 wby, and 30-378. I haven't found a reason to anneal.

Just some of my findings and opinions,
HPA
 
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