In my rugers I have never gotten good accuracy with 200 grain bullets from any of my 3 revolvers chambered for the 45 colt , My results start getting good with a 250 grain bullet . I have found that loads intended for the ruger and T/Cs and cheap cast bullets the lube on the bullets dosent work very well and I get leading , I have relubed some with the lee lube with good success . Try a 255 grain bullet and a starting load of 6.0 grains of Unique , The max is 8.5 until you get into the ruger and T/C loads .