Pharmseller is a big Big Game powder advocate, has the critters to show.
May want to PM him. Don't think he's a 140 TTSX fan, but should have some good info.
Edited to add, Barnes data shows BG as their accuracy powder with the 140 TTSX, 49.1 gr. at 2,910 fps. So, I'd assume BG may be the way to go if you can find some.
And, BTW, welcome to the Fire. Your PM may not work until you have more posts.
Last edited by Dirtfarmer; 11/17/23.