1-7 is a little tight for the 75's, most I know use 1-8. Althougth, the 1-7 should rock the 90's pretty well
In my neck of the woods, a fast twist 22-243 launching 75's or 80's is THE coyote medicine. They're rockin in the 3500-ish area, fast & flat with little to zero recoil.
Unfortunately, my 22-243 is a 1-12", no heavies for me but, 40grn blitzkings at 4600fps are kinda fun
I'd say do it,