I am currently working on a new load for a 16" TC Contender barrel.
In my Marlin 336 Cowboy version, 20 grains of Reloader 7 with a 170 grain Remington round nose bullet and it is an absolute deadly charm. Recoil is very mild. I have not put it on paper and it also, hits all targets at the rifle Silhouette Range. I have the scope mount elevated and Burris Signature Zee rings to get the needed elevation.
I have only recorded two with the #315 bullet & 20 gr Rel 7 with a 4 shot group with 3 shots in 0.87" and a flyer to 1.43". The second group measured 1 7/16th" with 7 shots. My buddy fire that one.
I also, use a Saeco #315 bullet (173 grains) and an Oregon Trail Bullet Company 170 grain with gas check. The Saeco is more accurate, but either one works great out to 200 meters and further.
I have just tried 16 grains of Alliant 2400, 9.2 gr of IMR SR 7625 and the Reloader 7 with a Saeco #316 150 grain cast bullet with a gas check. No definite results yet. Range day for tomorrow is cancelled due to weather, so I must wait until Friday.
Harold