IMR 7828 vs Reloder 22 in 257 Wby Mag.
 

Shooting 100 grain bullets. I need to get a different powder for my 257 Wby. Retumbo is a bust in this rifle, with very poor accuracy... and I've got better than 1/2lb left. :s6: And while RL-19 printed OK groups, it's a little fast for this size case and performance isn't up the Wby's standards (more like 25-06).

I've used IMR-7828 with 100 grain bullets, and had great results, but I've not been able to get it the last couple times I've been to the store. I'm going to go see what they have in stock, but I want to go with a couple alternatives in mind, since the selection is hit or miss. I was thinking I'd look for IMR-7828 or 7828SSC, or RL-22 as my top picks if they have either. Also thought about H-1000, Ramshot Magnum and RL-25, but I'm concerned that the latter may be too slow. So I'm looking for input and recommendations.

Mike

How about good ol H-4831?

I use RL22 in all my magnums, WBY, Win and Rem and it's always given me plenty of accuracy and velocity.

What's the 257 WBY's case capacity?

The 257 Wby will hold about 80 grains of water. 71 grains of IMR-7828 would fill them to right about the body/shoulder junction. 62 grains of RL-19 is well below the shoulder. I'd like to keep the load density between 85-95%, or 68-76 grains approximately.

Mike

Sounds like the case capacity is somewhere between a 7mm Rem Mag and a 300 Win Mag. RL22 would seem perfect. Then again, some rifles like some powders and not others.

I've had much better luck with RL22 than RL19. RL22 is my go-to powder for all our magnums.

Good luck with it.

RR,

You'd pick H-1000 over 7828? According to all the data I can find, 7828 seems to produce the best velocities with 100 grain bullets and over. H-1000 is slower than 7828, according to the charts, but produces less velocity with more powder... which is strange unless it's too slow as well. This is confusing.

Mike

If you can find Norma MRP, you can push a 100 gr. bullet 3642 f/s.

I use Norma MRP in my .340 Wby. Mag. using a 250 gr. Barnes "X" at 3062 f/s .408 three shot group at 100 yds. Good luck.

Ramshot Magnum out shot all the others with 100gr pills from my .257 Weatherby