.257 Roy & RL 25

[Guest]

I was just looking through the latest Hornady manual and noted that RL 25 produced the top velocity in a number of applications with the .257 Weatherby. Has anyone here tried the .257 Weatherby with the "newer" slow burners such as RL 25 and Retumbo? Specifically I am working on a load with the new 110 grain AccuBond.

 

[FOTIS]

I played with it a couple of years ago. No 110 AB back then. I basically started with the IMR 7828 loads (close to that powder's max) and substituted RL 25. When I reached the max with RL 25 I dropped a few grains and subbed Retumbo. Both worked nicely in the ROY. Gotta check my notes for details but I do know that I could get to 3400 fps with the 117 Hornady BT with either powder.

 

[Rwest]

I just worked up the 110 AB in my VG 257 WB. 74.0 GR H-1000
OCL 3.30 WB-cases Fed 215 P. VEL. 3380, Showed a E5 10.40 and a SD of 7.07. Grouped .25 at 100. I will be trying Retumbo soon. Let you know how that turns out. :grin:

 

[richcale]

I don't want to sound dumb, but what does E5 and SD stand for?

 

[Rwest]

E5 should read ES. (Extreme spread). The high minus the low velocity of a string of shots. Cony shows E5 because that is how the letter S looks on a crony. Most people call it E5 but really is ES.
SD, stands for (Standaed Deviation). This is the standard deviation of a string of shots.
:wink: