ricciadrdelli beat me out. I was going to recommend his site.
There is a lot of data for the 270 Weatherby but I could not find any using Retumbo. Have fun with it.
I am surprised that Hodgdon is not showing any loads for the round with Retumbo.
At one time I called Lyman regarding data on a new powder. They told me that it maybe add to their next loading manual. By the time the next manual was released the manufacture stop selling the powder I was interested in.
Option:
http://www.hodgdon.com/data/rifle/270wemag.phpIMR RIFLE DATA
NEVER Exceed the Loads Listed Here
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BULLET POWDER GR VEL CUP
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270 WEATHERBY MAG
CASE: WEATHERBY
BBL: 26"
PR: FEDERAL 215
TWIST: 1:12" TRIM: 2.539"
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100 GR. HDY SP
DIA: .277"
COL: 3.250"
IMR 7828 78.5C 3645 48,200 CUP
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130 GR. NOS PART
DIA: .277"
COL: 3.250"
IMR 7828 76.0 3500 53,000 CUP
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140 GR. HDY BTSP
DIA: .277"
COL: 3.295"
IMR 7828 73.5 3325 53,000 CUP
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150 GR. NOS PART
DIA: .277"
COL: 3.250"
IMR 7828 72.0 3215 53,600 CUP
C= Compressed Charge
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