Got a good used Ruger Blackhawk in .45 Colt last month to take on my antelope hunt in case I got a shot under 100yds. Put a 2.5x scope on it, read the manuals, and made up some loads that shot into 1.5" at 25yds. Should group about 6" at 100yds, right? Nope. Couldn't stay on a 12x12" target sheet off bags with no wind. Didn't have time to play load development, so the Ruger stayed home. I get the feeling that big fat pistol bullets may not stabilize as well as rifle rounds, but I expected better performance than "side of the barn" accuracy at 100 yds. I was shooting a 7.5" barrel, 1:16" rifling, Starline cases, 20.5gr of 296, CCI large pistol magnum primers, and 225gr Speer JHPs. No chrono available, but guesstimating from the books at about 1300 fps. No pressure signs. Any suggestions?