I have access to 6"Sec 6 and a 5-5/8 3 screw OM BlackHawk. I loaded some 170 HC Speer over 14.5 H110 from the rifle data section of the Lyman book . They're fantastic in the 18" 1894 C . I think that was when I broke my wrist the first time . I fired 2 in the Sec 6 thinking maybe my grip was bad the first time . My grip was fine not so much the load .