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MADISON · May 25, 2005, 06:21 AM

Special NECK SIZING DIES
I E-Mailed RCBS on December 12, 2004 and received the following response on December 15, 2004.

From an old #8 Speer Reloading Manual. You and other equipment manufacturers sell special NECK SIZING dies. Does this still apply to your equipment?

Neck Sizing is the term applied to the process of sizing only the neck of a case, with a special die which doesn’t touch the shoulder or body of the case. Neck sizing does eliminate excessive working of the case shoulder and body but, also, may size the neck off-center and leave the body of the case too large to chamber. A better way to reduce excessive working of the case body and shoulder metal is to use a full length sizing die but, use it so it only sizes partially. To do this, the full length sizing die is backed out of the tool so that the shoulder is not touched by the die. This preserves the important head and shoulder dimension and still sizes the neck normally. The body of the case centers the neck in the die and is sized enough to make chambering fairly easy in a bolt action.
Back the die off at least 1/16th of an inch [About one complete turn.]
Many shooters adjust their dies so that only half of the neck is sized. This leaves enough tension to hold the bullet securely for target or varment shooting

The RCBS “Ask the Expert Forum’s response was:
Yes, the necksizers only size the neck of the cases. And yes, there can be run-out after necksizing as there is nothing to support the base of the case - it just sizes the neck. AS FOR PARTIAL SIZING -- Many of our customers choose to do this - but, it is trial and error and sometimes the chamber v.s. die fit does not allow the reloader to partial size - they will not chamber afterwards.

May 25, 2005, 06:21 AM	#4
MADISON Senior Member Join Date: January 1, 2000 Location: Roanoke, Virginia Posts: 2,678	Special NECK SIZING DIES I E-Mailed RCBS on December 12, 2004 and received the following response on December 15, 2004. From an old #8 Speer Reloading Manual. You and other equipment manufacturers sell special NECK SIZING dies. Does this still apply to your equipment? Neck Sizing is the term applied to the process of sizing only the neck of a case, with a special die which doesn’t touch the shoulder or body of the case. Neck sizing does eliminate excessive working of the case shoulder and body but, also, may size the neck off-center and leave the body of the case too large to chamber. A better way to reduce excessive working of the case body and shoulder metal is to use a full length sizing die but, use it so it only sizes partially. To do this, the full length sizing die is backed out of the tool so that the shoulder is not touched by the die. This preserves the important head and shoulder dimension and still sizes the neck normally. The body of the case centers the neck in the die and is sized enough to make chambering fairly easy in a bolt action. Back the die off at least 1/16th of an inch [About one complete turn.] Many shooters adjust their dies so that only half of the neck is sized. This leaves enough tension to hold the bullet securely for target or varment shooting The RCBS “Ask the Expert Forum’s response was: Yes, the necksizers only size the neck of the cases. And yes, there can be run-out after necksizing as there is nothing to support the base of the case - it just sizes the neck. AS FOR PARTIAL SIZING -- Many of our customers choose to do this - but, it is trial and error and sometimes the chamber v.s. die fit does not allow the reloader to partial size - they will not chamber afterwards.