Neck turning?

Lavid2002 · May 15, 2008, 10:25 PM

Whats neck turning?
P.S. I have a lee 3 die set for .308 win. The deck sizing die is longetr than the full length sizing die....Do I have them mixed up the book has the pictures next to the naes and I figured ful length would be longer...no?

Ralph Allen · May 15, 2008, 11:05 PM

Your Lee 3 die set should have a sizing die, a bullet seating die, and a crimp die. Neck turning involves mic'ing the case neck and turning it with a special tool to get maximum accuracy. Look for any good reloading book and read it for some graet info, or most reloading suppliers have tips on their websites.
Ralph

Nnobby45 · May 15, 2008, 11:10 PM

If you measure the brass thickness on the neck with your micrometer, you'll notice that there can be a difference between minimum and maximum. If the difference is a lot, then the bullet will not be centered in relation to the case and chamber. This effects accuracy.

A special neck turning tool is used to make the neck thickness uniform.

Not much to worry about in hunting ammo. Match ammo is another story.

Don't confuse neck turning with neck trimming. Trimming needs to be done, since the case grows in length after being fired and full length sized. After a few firings (and sizings) the necks may need to be trimmed.

The excess brass that causes the case length to increase comes from the area of the brass near the case head. As it gets thinner, the chance of a case head seperation increases. Can't just keep trimming the neck. Proper head space will lessen the amount of case stretch.

Don't worry about the difference in the Neck die vs. the FL die. The neck die doesn't need to size the body of the case or contact the shoulder. The FL die is precise and made to strick tolerances.

You can't just keep shooting and neck sizing. After a few firings, the brass will begin to lose it's elasticity. It won't spring back and allow for easy extraction from the chamber.

You'll have to FL size then. Better, IMO, to FL size all along, but just enough for easy chambering without contributing to the above mentioned case stretch.

**Unclenick** · May 16, 2008, 01:10 AM

The Lee Deluxe die set for rifles includes the Lee Collet-style neck sizing die. Unlike the full length die that is just steel internally profiled to the final shape of the resized case, the neck sizing die is a mechanism that closes a collet around the neck to force it against a mandrel. The way the closing mechanism works is what accounts for the extra length. That die takes a bit of time to learn to use well and to get the feel of the right closing pressure. It's the only die I am aware of with a learning curve. But once you get it down, the resulting ammunition will be more accurate than you can get by full-length resizing, and the brass, if you learn to anneal the case necks and do a partial full-length resize (set the shoulder back about two thousandths) every five loadings or so, will have much longer life. Some benchrest shooters get up to 50 reloads from cases they take good care of. Five to ten is more normal for rifle cases being full length resized.

As to neck turning, as Nobby said, it is a way to uniform neck thickness. Most benchrest custom guns have their chambers cut with special reamers that leave the neck narrower than SAAMI standard chamber profile. A regular thickness neck can be too tight and unsafe in these chambers, so they have to turn them anyway. It takes a special tool that turns a cutter against the caseneck while it is centered on a mandrel.

If you have a standard commercial chamber and want some super accurate ammo but can live with 80% of your cases being a little less perfect, you can get a case measuring tool and sort them for the best cases and not bother with turning them. You can also just buy some Lapua or Norma brass. It is expensive, but is so uniform you usually don't need to do any kind of case prep with it at all. If you neck-size only, you can make it last long enough to justify the expense.

You need to be aware that neck-sized only ammo cannot be relied upon to feed from a magazine, but will need to be loaded singly. You want to do that anyway for best accuracy, because it is important not to knock the bullet out of alignment for highest accuracy, and going up a feed ramp can do that.

Lavid2002 · May 16, 2008, 12:07 PM

Thanks uncle nick! : D I didnt know about the magazine causeing the bullet to go out of alignment.

May 15, 2008, 10:25 PM	#1
Lavid2002 Senior Member Join Date: April 6, 2007 Posts: 2,568	Neck turning? Whats neck turning? P.S. I have a lee 3 die set for .308 win. The deck sizing die is longetr than the full length sizing die....Do I have them mixed up the book has the pictures next to the naes and I figured ful length would be longer...no? __________________ Math>Grammar

May 16, 2008, 01:10 AM	#4
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	The Lee Deluxe die set for rifles includes the Lee Collet-style neck sizing die. Unlike the full length die that is just steel internally profiled to the final shape of the resized case, the neck sizing die is a mechanism that closes a collet around the neck to force it against a mandrel. The way the closing mechanism works is what accounts for the extra length. That die takes a bit of time to learn to use well and to get the feel of the right closing pressure. It's the only die I am aware of with a learning curve. But once you get it down, the resulting ammunition will be more accurate than you can get by full-length resizing, and the brass, if you learn to anneal the case necks and do a partial full-length resize (set the shoulder back about two thousandths) every five loadings or so, will have much longer life. Some benchrest shooters get up to 50 reloads from cases they take good care of. Five to ten is more normal for rifle cases being full length resized. As to neck turning, as Nobby said, it is a way to uniform neck thickness. Most benchrest custom guns have their chambers cut with special reamers that leave the neck narrower than SAAMI standard chamber profile. A regular thickness neck can be too tight and unsafe in these chambers, so they have to turn them anyway. It takes a special tool that turns a cutter against the caseneck while it is centered on a mandrel. If you have a standard commercial chamber and want some super accurate ammo but can live with 80% of your cases being a little less perfect, you can get a case measuring tool and sort them for the best cases and not bother with turning them. You can also just buy some Lapua or Norma brass. It is expensive, but is so uniform you usually don't need to do any kind of case prep with it at all. If you neck-size only, you can make it last long enough to justify the expense. You need to be aware that neck-sized only ammo cannot be relied upon to feed from a magazine, but will need to be loaded singly. You want to do that anyway for best accuracy, because it is important not to knock the bullet out of alignment for highest accuracy, and going up a feed ramp can do that. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

May 16, 2008, 12:07 PM	#5
Lavid2002 Senior Member Join Date: April 6, 2007 Posts: 2,568	Thanks uncle nick! : D I didnt know about the magazine causeing the bullet to go out of alignment. __________________ Math>Grammar

May 15, 2008, 11:05 PM	#2
Ralph Allen Senior Member Join Date: January 21, 2007 Posts: 436	Your Lee 3 die set should have a sizing die, a bullet seating die, and a crimp die. Neck turning involves mic'ing the case neck and turning it with a special tool to get maximum accuracy. Look for any good reloading book and read it for some graet info, or most reloading suppliers have tips on their websites. Ralph

May 15, 2008, 11:10 PM	#3
Nnobby45 Senior Member Join Date: November 20, 2004 Posts: 3,150	If you measure the brass thickness on the neck with your micrometer, you'll notice that there can be a difference between minimum and maximum. If the difference is a lot, then the bullet will not be centered in relation to the case and chamber. This effects accuracy. A special neck turning tool is used to make the neck thickness uniform. Not much to worry about in hunting ammo. Match ammo is another story. Don't confuse neck turning with neck trimming. Trimming needs to be done, since the case grows in length after being fired and full length sized. After a few firings (and sizings) the necks may need to be trimmed. The excess brass that causes the case length to increase comes from the area of the brass near the case head. As it gets thinner, the chance of a case head seperation increases. Can't just keep trimming the neck. Proper head space will lessen the amount of case stretch. Don't worry about the difference in the Neck die vs. the FL die. The neck die doesn't need to size the body of the case or contact the shoulder. The FL die is precise and made to strick tolerances. You can't just keep shooting and neck sizing. After a few firings, the brass will begin to lose it's elasticity. It won't spring back and allow for easy extraction from the chamber. You'll have to FL size then. Better, IMO, to FL size all along, but just enough for easy chambering without contributing to the above mentioned case stretch.