I have been using 67gr RL25 and COAL of 3.27". This is in no way a max load, based on what Berger emailed me. I am thinking the COAL could be a tad longer and I'm sure the powder charge could be increased a little. This load gets me between .7-.8", not a worldbeater but decent hunting load.
What type of velocity were you getting at 67 grns of RL 25, and what was the barrel length juliang.
My friends and I have a total of five 257 Roy semi customs. All have 3 groove lilja SS barrels. Two are #5 profile and three are #3 profile. A Pacific Tool and Gauge reamer was used with Dave's special leade angle which is different than the original weatherby specs. Freebore was shortened as well. Two rifles use a .125" jump the other three use .070" jump to rifling. All rifles are using RL-25 with moly coated 115 Berger VLDs, Norma brass and Fed 215 match primers. Work up to max load listed for 115 BT shown in Nosler loading manual #6. I don't have my book nearby IIRC it was 72.5 or 73, best to check. Some of the rifles were able go past this amount with 74 grs. The 74 gr loads were worked up in 85 degree temps. Outstanding accuracy. Two elk, and five deer taken so far with excellent results.
For what it is worth your results may vary due to a different chamber, not using moly, number of grooves in barrel and mixing components. I hope it works out for you.
Azshooter if you don't mind could you look at your book to see what the velocity was with the respected grains of powder, and barrel length.
Guys the reason I'm asking is beause I got 1 whole 5 shot groups at 66.5 grns and 1 whole at 67.3 grains(RL25) with the Bergers at .030 of the lands, to say the least I couldn't chrono them because I had to send my CED sensors and computer back to CED. Thanks in advance. Will post picks tonight Lord willing and not forgetting to do so.
