neck sizing questions

[russt]

so ive been reloading for several years and have heard the term neck sizing but dont know anything about it. up until now ive full length sized everything, but i am interested in the pros and cons of neck sizing and what exactly it does different.

[Flyin Brian]

Neck sizing just tightens up the neck so it will have enough neck tension to firmly hold the bullet, without pushing the shoulder down. It's great if your shooting your ammo out of the same rifle all of the time, but if you have 2+ rifles and sharing ammo among them, the chambers may be different sizes so the brass shot in the larger chamber may not chamber in the smaller rifle.

Also, any new brass or brass found at the range needs to be full length sized until you "fire form" it to your chamber size.

Pros: brass lasts longer, supposedly more accurate.

Cons: Need to full length size and fire form brass first, possibility of rounds not chambering if you get them mixed up with another rifle's brass.

[Whiterabbit]

there are sections in selected chapters dedicated to discussing it in this book:



An awesome book. I DO recommend it for anyone who's reloaded a few times/years/decades. I've learned so much, and even stuff I never bothered to research, I read about it and think to myself "Oh I read a question on calguns in a thread title, this would absolutely answer that question!"

Happens constantly flipping through this reference.

[FLIGHT762]

N/O (neck only) sizing works for about 4 firings from the same rifle it was originally fired in. After 4 or so firings, you'll need to F/L (full length) size again.

N/O sizing works the brass less and can make your brass last a bit longer, but if you have your F/L sizing die properly set to bump the shoulder only about .002", you will also get long brass life. Before getting into N/O sizing, I recommend you get a digital set of calipers and bump gauge ( the Sinclair gauge works very well over the Hornady gauge) and set your F/L dies to bump the shoulder minimally. Many reloaders do not do this and they are beating their brass up.

This video explains it: http://www.youtube.com/watch?v=-n_l-bYxbg0

The cons for N/O I have found is; I only N/O size for ammunition that is going to be fired at the target range. Every once in a while, I get a N/O sized case that won't chamber and it gets stuck. I now mark my N/O reloads and F/L size after no more than 4 firings.

For all ammunition that I will be using for hunting / field use (even Varmint hunting) gets F/L sized.

N/O sizing is convenient, you don't have to use sizing lube and then have to remove it by hand or by tumbling. I N/O size when I'm developing loads. For me, it's mostly for convenience.

For times when I want 100% reliability chambering, I F/L size.

Since I didn't mention it, N/O sizing is for bolt guns only. Autoloaders, lever guns and pumps get F/L sized cases. N/O for these rifles and your looking at possibly getting a stuck case that will be very hard to remove. I've seen some blogs with shooters N/O sizing for their AR's, I WONT do it, you're setting yourself up for a kaboom.

[russt]

thanks for that i think i will stick with f/l for my guns, but i am going to look into a bump gauge and going that route, ive always just screwed the die in till it touches holder then went 1/4 more, never knew there is more to it. thanks

[rsrocket1]

For the headspace measurement on bottleneck cartridges, get the Hornady case gauge. That way you can measure the "as fired" shoulder height of your cases and adjust the f/l die to size a couple of mils (0.001") shorter than that measurement.