I recently became the proud owner of a 375 Ruger Alaskan, SS, laminate stock,23in. barrel. I am wanting to load 270 gr. round nose bullets @ 2500 fps. I have a little IMR4895 and quite a bit of Ramshot Tac. I would like to try Reloader 15 but so far cannot find any available. My question is has anyone tried Tac n their 375 Ruger and if so any starting loads. thanks for any information. This is my first post but have been enjoying this forum for years.

Can't pass along any info for loading the 375 Ruger with TAC. What I can say is that when I've called or emailed the folks at Ramshot Powders regarding load data for various cartridges or powders, they've been very helpful. That said, it'd be worth your time to give them a call. Let us know what you find out.

I have contacted them and they recommend Big Game and Hunter. They said that Tac was too fast to be a good powder in 375 Ruger. I have seen loads listed for H4895 / IMR4895 and Tac is rated right along with them ( fast to slow ).I realize Tac may not be optimum for the 375 Ruger .

The burn rates for those chrts is conducted in a closed container and do not simulate the expanding chamber of a rifle or pistol chamber as the bulletr allows the chamber to "expand" as the bullet travels down the barrel.
This is important because smokeless powder burns faster with increases in pressure. when you put a powder into a cartridge that is listed as "close to" another powder you may find that you end up with big differences in pressure and velocity.

If a powder is not recommended for your cartridge DON'T USE IT!

PaulS
Thanks for the reply. I was able to purchase some IMR4895 yesterday so will go with that. There is published data for that powder and my bullet selection. I will be looking for a moderate load to get used to the rifle and cartridge.