Please explain neck uniforming/turning

Banzai · July 6, 2000, 05:13 PM

Someone please explain neck turning to me. I know that the benchrest crowd uses this to pare down the neck size to allow their ultra accurate cartridges to fit their ultra tight throats.
It seems to me that uniforming the neck walls would be a good thing overall, but which operation is done first? Do you turn the outside first? How about the inside? Where does case sizing fall in the sequence? Some of the specilaity dies recommend expanding as a seperate step?
The reason that I ask is that recently, I have been reloading bulk for an AR. I started noticing that the insides of the neck, where it meets the shoulder, is starting to grow the dreaded "donut" and I can feel when the bullet seats against, and then passes this ridge. Can this be overcome in any other method? Am I approaching the end of the service life of this brass (mixed lot WCC and LC)? How many loads should I expect (I know this depends on lot, powder, and power levels, but I mean in general)?
OK, I may never NEED to do any of this, but it's another chance to buy some really cool tools!

Thanks in advance.

Tom

------------------
A "Miss" is the ultimate overpenetration!
You can never be too rich, too skinny, or too well armed!
Wake up and realize that you have the moral imperative of action..!!!

[This message has been edited by Banzai (edited July 06, 2000).]

swifter... · July 9, 2000, 11:19 AM

You really need to get a Sinclair Manual (& catalog!) for a really detailed explanation.
In passing, I'll say that outside turning is the best way. Inside reaming will follow the hole, so if one wall's thinner to start with, it will be thinner at the end. Outside turning will uniform the case necks. Don't try for a 100% clean-up, 60-75% works fine on factory chambers.
K&M )I think) has a new tool to remove the donut, but you can get it out by using a neck expander - moving the donut to the outside - and neck turning.
Hope this helped, but I really recommend reading some advanced reloading books to get all the data you need!

------------------
The Bill of Rights, and the Golden Rule are enough for civilized behavior. The rest is window dressing. Shoot carefully, swifter...

Banzai · July 9, 2000, 06:41 PM

Does Sinclair have a web address or a phone # that I could get in touch with them?

Tom

------------------
A "Miss" is the ultimate overpenetration!
You can never be too rich, too skinny, or too well armed!
Wake up and realize that you have the moral imperative of action..!!!

bfoster · July 10, 2000, 01:25 PM

Sinclair has a minimal website: http://www.sinclairintl.com/

The phone number is listed on the page.

Neck turning is essential with the precision chambers in my bench rifles, but it has resulted in minimal gain in group size with all but one of my factory varmint rifles. It isn't a bad idea, particularily if you limit yourself to 80% or so clean up, just be pleasantly surprised if you see a big improvement for a fair amount of effort.

If you are inclined to try this, check out Sinclairs' setup for neck turning using a power screwdriver. They also sell a jig that makes tool setup a breeze. I no longer bother to use a lathe for most neck turning; this outfit gives excelent results..

Bob

[This message has been edited by bfoster (edited July 10, 2000).]

July 6, 2000, 05:13 PM	#1
Banzai Senior Member Join Date: January 29, 2000 Posts: 275	Someone please explain neck turning to me. I know that the benchrest crowd uses this to pare down the neck size to allow their ultra accurate cartridges to fit their ultra tight throats. It seems to me that uniforming the neck walls would be a good thing overall, but which operation is done first? Do you turn the outside first? How about the inside? Where does case sizing fall in the sequence? Some of the specilaity dies recommend expanding as a seperate step? The reason that I ask is that recently, I have been reloading bulk for an AR. I started noticing that the insides of the neck, where it meets the shoulder, is starting to grow the dreaded "donut" and I can feel when the bullet seats against, and then passes this ridge. Can this be overcome in any other method? Am I approaching the end of the service life of this brass (mixed lot WCC and LC)? How many loads should I expect (I know this depends on lot, powder, and power levels, but I mean in general)? OK, I may never NEED to do any of this, but it's another chance to buy some really cool tools! Thanks in advance. Tom ------------------ A "Miss" is the ultimate overpenetration! You can never be too rich, too skinny, or too well armed! Wake up and realize that you have the moral imperative of action..!!! [This message has been edited by Banzai (edited July 06, 2000).]

July 9, 2000, 11:19 AM	#2
swifter... Senior Member Join Date: March 16, 1999 Location: So. CA Mountains Posts: 540	You really need to get a Sinclair Manual (& catalog!) for a really detailed explanation. In passing, I'll say that outside turning is the best way. Inside reaming will follow the hole, so if one wall's thinner to start with, it will be thinner at the end. Outside turning will uniform the case necks. Don't try for a 100% clean-up, 60-75% works fine on factory chambers. K&M )I think) has a new tool to remove the donut, but you can get it out by using a neck expander - moving the donut to the outside - and neck turning. Hope this helped, but I really recommend reading some advanced reloading books to get all the data you need! ------------------ The Bill of Rights, and the Golden Rule are enough for civilized behavior. The rest is window dressing. Shoot carefully, swifter...

July 9, 2000, 06:41 PM	#3
Banzai Senior Member Join Date: January 29, 2000 Posts: 275	Does Sinclair have a web address or a phone # that I could get in touch with them? Tom ------------------ A "Miss" is the ultimate overpenetration! You can never be too rich, too skinny, or too well armed! Wake up and realize that you have the moral imperative of action..!!!

July 10, 2000, 01:25 PM	#4
bfoster Senior Member Join Date: October 13, 1998 Location: N. of Fords Switch, OK, USA Posts: 297	Sinclair has a minimal website: http://www.sinclairintl.com/ The phone number is listed on the page. Neck turning is essential with the precision chambers in my bench rifles, but it has resulted in minimal gain in group size with all but one of my factory varmint rifles. It isn't a bad idea, particularily if you limit yourself to 80% or so clean up, just be pleasantly surprised if you see a big improvement for a fair amount of effort. If you are inclined to try this, check out Sinclairs' setup for neck turning using a power screwdriver. They also sell a jig that makes tool setup a breeze. I no longer bother to use a lathe for most neck turning; this outfit gives excelent results.. Bob [This message has been edited by bfoster (edited July 10, 2000).]