60.5g of Retumbo w/100g nbt is what I use in my 24" shilen. I have a fast barrel. Not complaining though.
I get 3250fps with 115g nbt's and 57g Retumbo in the same rifle.
No pressure, signs, great accuracy, 1/2 MOA from both.
Use win cases, WLR primers, and OAL of 3.250"
I'm not saying every 25-06 will reach 3500fps safely and accurately, but mine does, and I"m very happy with it. This is my 4th one now and its the only one I"ve tried Retumbo in, so I cant compare it to the other rifles. However with the other 3 rifles, 3400 was all I could get with Rl-22 and IMR-4831.
Retumbo is definately worth looking into though IMO. One of the better powders for the 25-06 w/100-120g bullets.