12 grains to 15 grains of blue dot powder research says at 15 grains its at 1200 per fps with a 255 grain cast swc. Research doesn't say what make of pistol they using. Knowing blue dot hot powder anybody that load to much for a newer Vaquero
[SIZE="3"][B]5 1/2" USFA Rodeo [/B]
250 LRN (.452") 8.5 grs Unique thrown, R-P cases, CCI300 primers
12-May-02 T = 80°F
Ave Vel = 855
Std Dev = 16
ES 59.91
High 885.4
Low 825.5
Number Shots 12
250 LRN (.452") 11.5 grs Blue Dot R-P cases, WLP
11-Sep-05 T = 85 °F shoots close to point of aim acceptable accuracy
Ave Vel = 845
Std Dev = 48
ES 183.6
High 933.3
Low 749.7
N = 18
250 LRN (.452") 12.0 grs Blue Dot R-P cases, WLP
11-Sep-05 T = 85 °F shoots close to point of aim good accuracy
Ave Vel = 904
Std Dev = 44
ES 149.6
High 955.2
Low 806
N = 15 [/SIZE]
That extreme spread is telling you something. I suspect the pressure is not high enough with that charge of Blue Dot to fully combust.5 1/2" USFA Rodeo
250 LRN (.452") 8.5 grs Unique thrown, R-P cases, CCI300 primers
12-May-02 T = 80°F
Ave Vel = 855
Std Dev = 16
ES 59.91
High 885.4
Low 825.5
Number Shots 12
250 LRN (.452") 11.5 grs Blue Dot R-P cases, WLP
11-Sep-05 T = 85 °F shoots close to point of aim acceptable accuracy
Ave Vel = 845
Std Dev = 48
ES 183.6
High 933.3
Low 749.7
N = 18