Loads I tried that grouped well when my 5.5 Bisley was new last year, were 23.5 grains of IMR 4227 and 25.5 grains of H110 under a 250 Speer Deep Curl using Winchester brass and Federal GM large pistol primers. Both printed 5 shots into 1.5" at 25 yards off a bag. The H110 has a deeper bark and sharper bite.
If you have a convertible ACP cylinder, 9.4 grains of Longshot sent 5 230 XTP's into an inch and a third at 25.
That's all the load development I've done for the gun so far. Haven't had a chance or material to slug chambers and barrel yet, so no hard cast till then.
I'm thinking since I've gotten some decent groups with the gun and have noticed no issues, my chambers must be acceptably sized. I'll know more about that when I slug them, I guess.
