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Old 01-13-2012, 12:47 PM
PeterS PeterS is offline
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Join Date: Feb 2009
Location: New York
Posts: 147
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Andy, The 14 twist should work fine for 40's. Long (usually heavy) bullets require a faster twist. A good example is the 6.5x55 Swedish Mauser that originally was issued with 156gr bullets and had a matching 1:9 (1:8.66) twist. Historically speaking, the 14 twist was pretty standard in the .222 for bullets up to 53gr, which are certainly longer than the 40's. What reamer is your smith going to use? Long leade and freebore has been a frustration for me and that is in part why I stayed away from the 40's in the factory rifles. I was not able to reach even .020" off the rifling and still have enough of the bullet in the neck. I don't recall the dimensions but I am sure I recorded them at the time. They may have worked fine jumping, but I focused more on the 50's, 52's and 53's. Some of the guys here can perhaps shed more light on this but it would be nice to be able to have the bullets touch the rifling and still have about .224" of the bullet in the neck. Especially if you have a choice in a new build. Frequent hard, gusty winds were the other contributing factor for me.

Take care, Peter.
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Last edited by PeterS; 01-24-2012 at 08:44 PM.
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