I've decided to get into a 22 Cheetah MK1. I have a set of Redding dies marked 22 Cheetah 40 Degree NK and my seating die. I was thinking I simply run a 243 Win through the neck die and fireform. Well, I raised the ram arm on my Rock Chucker all the way and screwed the die down until it hit the shell holder. After I ran my first 243 through, I quickly realized I just ruined it. The shoulder and neck were crushed!
I'm kind of new to reloading as you can tell but thought I had enough exper to form my brass! I loaded a couple of hundred rounds of 260 REM and 300 WIN but no wildcats.

HELP!

Could it be a NK Neck sizing die instead of 40 degree neck. Dr. Howell's book shows that cartridge with a 40 degree 40minute neck. I would look into an RCBS or Redding forming die. Dr. Howell's book mentions RCBS. All the Redding dies I have say FL for full length and NK for neck sizing die.

Hope this helps!

Mike

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Victory through superior firepower!

[This message has been edited by ready_on_the_right (edited 08-28-2001).]

This is a simplistic answer to a fairly complex problem. First never set your die to where it touches your shell holder in the up position...your just begging to create excess headspace. Second, and this is a bit tricky, you need to carefully just neck a portion of the neck down from .243 to .223 caliber...how much of the neck to size will depend on how your chamber is cut but basically you need to size just enough so that when you chamber a round with a seated bullet the bolt will close a little hard. This will insure that you form the case properly by blowly out (fire-forming) the neck to the proper position and angle. Let me suggest you go over to www.benchrest.com and pose this question..these guys are experts and can give you a more detailed answer than I can. This is not a tough thing to do once you underrstand how to do it. Good luck