Collet neck sizer vs neck sizing die

blancoman · January 22, 2007, 02:24 PM

I noticed that Lee has a Collet neck sizing die for bottleneck cartridges. I use a neck sizing die for my 06, 308, and 243 but they are not Lee they are RCBS and the word Collet is not on the RCBS die box. Is a Collet die the same as a standard neck sizing die.

Smokey Joe · January 22, 2007, 03:26 PM

Blancoman--A "regular" neck sizing die will first squeeze the case neck down a bit too far, then size it right by pulling a sizing button up through it. Nothing wrong with that as far as getting the sizing right, and it's been done for many years.

A Lee Collet die will just squeeze the case neck to the correct size in the first place, by squeezing the neck between a precisely sized mandrel on the inside, and the collet on the outside. Lee claims that this will result in more accurate ammunition--Don't know about the comparison, but the Collet Die DOES make accurate ammo.

The real advantage as I see it is that the Collet Die only works the brass of the neck once in resizing, compared to working the brass twice with the other type of die. Working brass tends over time to make it brittle, resulting eventually in split case necks, so the fewer times a piece of brass is worked, the longer it lasts.

I believe that Lee owns patents on the collet neck-sizing die, so, no, yr RCBS dies won't be of that type.

I have Lee Collet Dies for neck sizing, in several cartridges, and am very happy with the results obtained from them. However, were I you, I would NOT rush right out and replace all my "regular" neck sizing dies with Lee Collet neck-sizing dies. I would, however, try a LCNSD the next time I was setting myself up with dies for a new cartridge.

blancoman · January 22, 2007, 03:30 PM

That was the answer I was looking for. Probably gonna be a while before I need a new set of dies but at least now I know. Thanks again.

January 22, 2007, 02:24 PM	#1
blancoman Member Join Date: December 28, 2006 Posts: 37	Collet neck sizer vs neck sizing die I noticed that Lee has a Collet neck sizing die for bottleneck cartridges. I use a neck sizing die for my 06, 308, and 243 but they are not Lee they are RCBS and the word Collet is not on the RCBS die box. Is a Collet die the same as a standard neck sizing die.

January 22, 2007, 03:26 PM	#2
Smokey Joe Senior Member Join Date: July 14, 2001 Location: State of Confusion Posts: 2,106	The answer is "no." Blancoman--A "regular" neck sizing die will first squeeze the case neck down a bit too far, then size it right by pulling a sizing button up through it. Nothing wrong with that as far as getting the sizing right, and it's been done for many years. A Lee Collet die will just squeeze the case neck to the correct size in the first place, by squeezing the neck between a precisely sized mandrel on the inside, and the collet on the outside. Lee claims that this will result in more accurate ammunition--Don't know about the comparison, but the Collet Die DOES make accurate ammo. The real advantage as I see it is that the Collet Die only works the brass of the neck once in resizing, compared to working the brass twice with the other type of die. Working brass tends over time to make it brittle, resulting eventually in split case necks, so the fewer times a piece of brass is worked, the longer it lasts. I believe that Lee owns patents on the collet neck-sizing die, so, no, yr RCBS dies won't be of that type. I have Lee Collet Dies for neck sizing, in several cartridges, and am very happy with the results obtained from them. However, were I you, I would NOT rush right out and replace all my "regular" neck sizing dies with Lee Collet neck-sizing dies. I would, however, try a LCNSD the next time I was setting myself up with dies for a new cartridge. __________________ God Bless America --Smokey Joe

January 22, 2007, 03:30 PM	#3
blancoman Member Join Date: December 28, 2006 Posts: 37	That was the answer I was looking for. Probably gonna be a while before I need a new set of dies but at least now I know. Thanks again.