I shot silhouette for a few years with the 44 mag. I always used bullets of about 250 grain, plus or minus depending on the aloy. I usually used flat base, but had the same bullet in gas check. I used a 6½ inch Smith & Wesson, a 7½ inch Super Blackhawk and a 10 inch Super Blackhawk. I could get the most velocity from the 7½ Ruger, I think because of its tighter fit on the cylinder.
But I found out you don't need 1500 fps at the muzzle to take the rams legs out! As a matter of fact, check the ballistics, if you can, and you will see that the bullet starting out at 1300 fps, gets to 200 metres at very little less speed than the same bullet starting out at 1500. 1200 fps at the muzzle is really all you need.
Most important is to sight in at all the different ranges, and keep your sight chart with you. That is, when you are sighted at 50 metres, see how many clicks you need to be on at 100. When you get that, mark it on your chart and go to 150, and finally the 200 meters.
I never changed the sights for windage. I just took a guess if the wind got up and held off the side of where I wanted to hit.
My loads were either H110/W296, or the old Hurcules 2400. I just cut back from max loads to get the velocity I wanted.
I KNOW, I KNOW. Winchester says to not reduce the loads of their 296, but I have used H110 for many years befor W296 came out and many of us found
H110 to be a very good powder for reduced loads.
The old standby, full power load in a 44 magnum is 22 grains of Hurcules
2400. I found this to be still accurate down to 19 grains, or less.