Never tried Retumbo until recently and haven't done enough work to draw definite conclusions, but initial results have been promising in a new Sendero in 7mm Remington Magnum. I've used several bullets including the 150 and 160 Partitions. Looks like this powder may outshoot H4831, the powder I've used almost exclusively because of good accuracy results for a long time in several magnum cartridges.

Anyone with more experience care to comment on Retumbo?

I haven't tried Retumbo,but I find Reloader-22 to work real well in te 7mag.

Use it in my 30/378.
I use LOTS of it.
Lol

A friend of mine says it's the cat's meow in his 7mag. I believe he's shooting the 168 grain Berger's.

It works great in the 7mm Rem mag!

I've happily used Retumbo in both the .300 Rem Ultra Mag with 200 gr bullets, and later in the 25-06 with the 115 gr bullets.

Very happy with the velocity and accuracy from both.

Guy

Works great in the 264 WM too which isn't too different than your 7 mm RM. If you are getting good results it's a good powder to stay with.

It's the R-26 of yesteryear.

It is awesome in 25-06 with 110-120 grain bullets. I've tried in in 280AI with 150's...not as impressive in that scenario.