I posted a ten shot group with 25 Varget and the 75 BTHP that’s an inch.
How much better do you think that barrel should be?
I couldn't find where you said what barrel it is, & even if I knew, it would be hard to tell how good it could be.
Regardless of what some like to think, 10 shots <MOA is not all that easy to get to & is surely not a given. But some here like to obsess with it.
Varget is generally a good performer, but it meters like rocks for any volume loading so I really don't use it but if it works, then use it.
As has been stated before 8208 is generally accurate as is AR-Comp, TAC & some of the V V powders. If your gun really doesn't like 75, then try some 77's or 69's from Sierra.............the TMK's in 69 have been very good for me.
I don't user Lever, as for the most part, I just think it's too slow & there are better choices, other than that I can't comment on it, but it's definitely now very impressive in your gun.
MM