Re: Reloading suggestions for Pre-64 Mod 70 264 Win Mag
I have found that the accuracy load listed on the Nosler website, using 140g partitions and 55.0 grains of RL22 is very accurate. It is also VERY slow, putting you in the same velocity range as a 6.5x55. I used it as my hunting load this year because I was hunting in the woods and expecting close range shots.
I have also developed accurate loads using the 140g Partition with Retumbo. I worked up using Hodgdon data (also listed on their website). Max is 63.5 grains. Best accuracy came in at 62.6 grains, produced .6" groups @ 100 yards, and chronoed just a hair under 3000fps.
Keep in mind that the fairly blunt design of the Partition, along with its long bearing surface, tends to reach pressure limits more quickly than the newer VLD type designs. Most guys I have seen shooting VLD's are getting 3100+fps with their handloads. I plan to develop loads using Hornady AMAX's and Berger VLD's, but haven't gotten that far yet.
From the research I have done, Retumbo seems to be THE powder for the .264WM. I have also seen MAGPRO recommended, but have not tried it. I recently bought some RL33 to see how it does, but won't have the chance to experiment with it for a few months yet.
Bear in mind that my rifle is a recent production Model 70, so I don't know if the chamber and bore dimensions are different from your rifle or not.