Author Topic: When should I peel necks/outside neck turn cases? (Read 378 times)

Selmer · « **on:** February 02, 2005, 07:41:05 AM »

I have a Forster case trimmer that I bought used with one collet, three pilots, and a couple attachments I couldn't figure out for a while, all for $15 in excellent condition.

I got online and was looking at Forster accessories and realized I have a outside neck-turning attachement, with the exception of a small stop that fits into the base. My question is, when do I need to turn necks? I measure my necks and the outside diameter after resizing is either the same or just under the measurements in my manuals. Judging by what little I know about machining (which is a little bit), my Forster is a mini-lathe, and a darn good one, so would turning my necks center the neck in relation to the axis of the case because it's being held in place and centered by a brown & sharpe collet and a mandrel (pilot), thereby making the entire more in line with the axis of the chamber and helping to center my bullet in the bore before things go boom, and eliminating one more gremlin hiding in my gun? Let me know what you guys know and have experienced with this. Thanks for the info!
Selmer

Catfish · « **Reply #1 on:** February 02, 2005, 12:58:00 PM »

If your shooting a factory chamber never turn your case necks. If you do you will only increase you neck expantion and shorten case life. Neck turning is for tight necked chambers only. I like my cases to expand abt. .002 when fired and with factory chambers your way over that, probibly .010 anyway.

Selmer · « **Reply #2 on:** February 03, 2005, 04:02:42 AM »

So I shouldn't be turning necks even to take out a high spot? Or doesn't it really matter and I should save this fun case prep exercise for my custom chambered .223 16.5" Encore barrel? (which is a pipe dream right now, maybe after seminary, but it's nice to know I got a heck of a deal with the case trimmer!)
Selmer

Robert · « **Reply #3 on:** February 03, 2005, 05:31:58 AM »

In addition to what Catfish posted....neck-turning is sometimes required for when you neck-down brass to a smaller caliber. For example making 7-08 brass from 308 Winchester. The brass could get thicker when sized-down and cause the bullet to be pinched in the throat when chambered, or could collapse shoulders when attempting to chamber. On the other hand..when necking-UP, for instance...7TCU from 223 Winchester....this makes the neck thinner, and has a tendency to cause black necks from the blow-back. I don't know of a cure for this, except buying brass that is manufactured specifically for the wildcat chambers rather than re-forming.

dave375hh · « **Reply #4 on:** February 03, 2005, 07:22:50 AM »

Selmer,
Neck turning is normally done for varmint and/or target rifles. It will benefit factory chambered rifles but only to the extent that it will make your neck wall thickness even. In theory it allows the neck to release the bullet uniformly because the neck is of equal thickness. As far as straightness is concerned that is a function of your reloading dies, press, and your technique. Mearly turning the necks won't correct a problem that exists in these other areas. Also a neck that is overly thick on one side is probably thick in the body also, and should be culled. I check neck runout before I turn them to find any that are more than .003 out these I cull. I did 300 pcs of Norma brass and found 293 of them were .001 or less so I didn't bother to turn them. Norma brass is expensive but it's very good stuff. To see the benefit of neck turning everything else must be up to snuff or you'll just be wasting your time. Basicly it's one of the little things you do when your looking to gain a 0.1 of an inch, not 1/2 an inch.