Load Development 300Wthby and Retumbo

[bkondeff]

Doing load development and need max load for 300 Weatherby using Retumbo Powder on 180gr for both Accubond and BTip's. Using Weatherby cases in a Weatherby Mark V.

I tried doing research here and other forums, as well as Nosler and Hodgdon Manual with only one post claiming 88.0 grain load(not referenced as max).

It seems that H1000 and RL22 are favorites, and are powders I have, so will start with about 1.50 grains below max on those(87.0gr and 79.0gr respectively). I also have RL19, and IMR 4350 and 4831 but research says to try these if slower powders don't produce. I was suprised not to find more references to the use of Retumbo, though Hodgdon does list a max load of 84.5g for 200 gr bullets so maybe the bullet choice is relatively light.

Any help on Retumbo load would be helpful.

 

[RT2506]

I really don't think you can get too much Retumbo into your 300 Wthby case to be over pressure with a 180 gr bullet. I did get too much pressure with the max load listed for 130 Nosler Accubonds in a 264 Win mag though with Retumbo but dropping down 1 full grain still gave me 100 fps more over any other powder I had tried. I do have to admit that the day I tried the max load in the 264 mag the temp was 87*.

 

[lamiglas]

I shoot the nosler ab 200 grain in my 300 rum and it shoots very well, so we tried to find a load for it in our 300 wby. we tried retumbo and h-1000 and never could get it quite to an inch. We then tried a 210 berger and started at the lowest load berger gave me and loaded up 10 to mag length. right off the bat it is shooting 1/2 moa. i just wanted to mention this because if you have trouble with the ab, you might try the berger. good luck to you and hope you find a good load.