Retumbo in a .300 Winchester Magnum

[tillroot1]

Hello, new here and looking for some information and opinions: I would like to try Retumbo in my .300 win mag, is anyone using it and if so, what is a good starting point? what is the burn rate simular to? thanks in advance, Ron Tilley

 

[kraky]

Go to Hogdon.com and you will see all their recomended loads for all their powders including retumbo. I've gone up to 83.5 under a 200 grain bullet and gotten 2930 fps without pressure signs in a tikka t3 light. I've gotten some mixed reactions running it under 180 grainers.
Bottom line is it is slower than H1000 by a bit. You will also have super highly compressed loads with the long 180 and 200 grain bullets. If I had to give you advice I'd say start with max h1000 loads and work up closely watching pressure and watching for wild velocity swings.
Retumbo did work wonderfully for me in a super fussy 300wby UL. This gun had trouble shooting alot of bullets to 6-9" groups at 300 yds. Then with retumbo the gun would shoot moa with both the 200ab and the 180 tsx. (Me thinks the gun has a terribly stressed barrel).

 

[pjracer]

retumbo

works well in my sako. work up slowly. i am shooting berger vlds 190 and 210 gr.

 

[victor]

Very Interesting Kraky,

I have a .300Wby UL as well. I use 84.5gr of MRP with 200 Accubonds and have had 5/8" groups at 100yds. Then weeks later, same load and I get 1.25" groups.

Same exact load with H1000 gives me the same results. Too **** inconsistent!
Me thinks the barrel is just too thin & has internal stresses.
Just out of curiosity how many grains of Retumbo to you use in your .300Wby?

Thanks,
Vic

 

[kraky]

I'm doing just a tad over 88 for the 180's and 86 for the 200 ab. This with both rem brass and wby brass. The wby brass is about 30 fps slower. I also did a test at 60 degrees and one at 25 degrees and found no diff in velocity.
I sure wish my UL shot like my older jap built alaskan.....that would solve the problem quickly.

 

[littletoes]

Picked up a couple of pounds of Retumbo to try in my 300 Weatherby, but as of yet haven't tried it yet. I have used Reloader 25 a few times, with some good results, some not so great as of yet.

My Weatherby has a 1 in 9 1/2 twist, and I would realy like to try some Sierra 240's, just to see if they stabilize.

I've gotten 3150 fps using R25 to push a 200 grn SMK, but that got me some pressure signs, so I backed off. Groups just wern't what I wanted either.

I need to decide if I want to stick with the 200 or try the 240 SMK. I like the heavies better at longer ranges....

 

[280AIman]

Work up slowly and you will be good its a great powder and very consistant.