Hi,
Looking for new loads for my .300 Weatherby with 172gr Speer Impact other than the one supply by Speer, because the only powder I have from their data is with IMR-4831 and I have a lot of IMR-7828SSC and RL-22 and no data,that are very good for the .300. Anyone has tried other powders.

If you can find data for 180gr use that.

quote:

Originally posted by p dog shooter:
If you can find data for 180gr use that.

Not this time,Anyway I will work up some loads with the powder I have but here is some data from Speer manual #14 I have compare to what they give for their new bullets:
180gr. Grand Slam or Hot core with Reloder 19, max= 78.0gr.
165gr. Grand Slam or Hot core with Reloder 19, max= 80.0gr.
and for the 172gr. Impact with Reloder 19, max= 85.5gr. As you can see there is something different in the construction of their new bullet if you can go that high for the max load with that powder

I had my best velocity with 7828 back in the day..

Me too I had best result with IMR7828SC with other bullets but not with the Intact bullets I could'nt get better than 4'' group. I will have to go with their data included in the box