I'm getting ready to start loading for a .257 Weatherby rifle, so I thought I'd see if anyone has some well-proven loads to recommend. I can try about any powder, although my first will probably be RL22. I've never owned a Weatherby before, don't like the looks of the action, stock, and appears cheap but isn't, but the thing shoots great. It has a slick action, decent trigger, and shoots 100-gr Hornady factory loads .650 for three shots at 3756fps. I suspected this factory ammunition was plenty hot, and case head expansion is almost .002!

I found I got the best groups in my rifle with RL25

I use the 100 gr Nosler partitions in my Accumark. 71.5 gr of RL 22 gives me 3650 fps or so and 2" groups at 300 yds.

Where are you measuring your case head expansion at? With what tool?
What bullets were being pushed with the Re-25?

I was shooting 120 gr Hornady HP with 70 grs of RL25 with a std primer. No other bullet or powder combinations even came close to the groups this combo produces in my rifle.

I found the best accuracy with h-1000 behind 100gr ballistic tips.The factory barrel would do no better than 1" but the custom barrel I had installed easily averaged less than 1/2".

To answer mclevela, I measured at the case head,as always with a 1" mike. Avg about.0018 expansion. I normally don't want anything over .001-.0013. I haven't started loading the .257 yet, just fired a few factory loads. As I said, they seem a little hot, and the velocity seems a bit high, too. I even fired some others over it to be sure, they were right on compared to previous rounds. I have shot up a lot of RL22 in 7mm Mag, and thought I would try it first, RL25 may be best with 120 gr.

My .257 seems to favor the Re-22 powder with the 100 to 120 gr. bullet weights. I have not used any primer other than the Fed. 215M but I am thinking of trying the Fed. or CCI 200.