I’m pretty sure even the new vaquero 44 mag also uses the old XR3 size grip frame just as the NM FLATTOP 44 mag does.These grip frames were modified in 1972/1973 for the new trigger spring and safety transfer bar, but they retained the same basic profile. These frames are on the New Model Single-Six, Super Single-Six, Blackhawk, Super Blackhawk with 4-5/8" & 5-1/2" barrel, the 1993-2005 Vaquero, & the New Vaquero .44 Magnum. (They do not fit the Flattop Blackhawks.)