Lyman's data indicates 4895 will give you the lowest pressures. Their data was shot in the standard 24" barrel, and you'll loose 100-150 fps in your barrel. For 180 at 2265 from 18", every powder they tested looks as if it will stay below SAAMI's recommended pressure. I'd use 4895 or maybe even 3031. They didn't test 760, but older pressure tested data from Winchester indicates it would also do the job for you.