Go for it, Homer. I used to practice on a standard ram silhouette laying on the 320 meter berm at our "Town" range with my 4", M29.

I was usually good for 5 out of 6, 6 odd time, both hands resting on sand bags.

Your rifle will do amazingly well at even longer ranges.

Elmer Keith is noted as saying that hitting at long range with a handgun was purely accidental, but if you practice at long range with your handgun, you'll have more long range accidents than someone who doesn't.

Same goes for rifle shooting.

My 16" bl. Model 94Trapper in .45 Colt used 25.0gr. W296 with a .452" 300gr.FNHP from a modified .458" RCBS 300gr. mould (I lubed then re-sized them). They were amazing & accurate as well, running around 1,550fps. I used that load to shoot 2 elk.
This load was reported to run .44 mag pressures in .45 Colt cases though R. Sefreid's testing many years ago.