Thanks for all the info guys. I'll start with the ret, and h 1000. But I'm real tempted to try the rl 25. Most the guys who run it seem like their getting a little more vel. I'm just worried about the vel swings with the temp.
The Barnes recommended .050 off the lands and that is where I loaded them. The Noslers I would start with .010 off the lands and see how it shoots. I shot 3 boxes of nosler 250's and couldn't get them to group in my rifle with 4 different kinds of powders and all sorts of seating depth's.
Stay away from the RL powders, the hotter it got here in Az. the hotter my test loads got. I have had no temp issues with H 4831SC they shoot the same place all the time.
What barrel are you using? I've got a couple boxes of 250gr nab I was Gona try after the 225.
Retumbo worked best in my 338RUM and 300 RUM. And everybody has talked about Retumbo not being temperature sensitive and that's why I was so glad it grouped best in my rifles. I did not want to have summer and winter loads like you have to do sometimes with other powders when you are on the upper ends of the powder scale.