The 'XR3-red grips are a little longer in the nose. When Ruger went to those grips and grip frames, all the full sized guns were fitted with them. (except the bird's head, and SBH of course) When Ruger came out with the 'New' Vaquero, they went back to the original size grip frame, with the grips hollowed out in the back to clear the lock mechanism. The XR3-red grips are a little longer in the nose, about a 1/10 of an inch. That pushed the grip back a little more from the trigger guard to protect your middle finger from the recoil. I like the new 'smaller' grip frames, but I do get 'whacked' more often with the trigger guard with full loads. So you have the XR3 (colt style grips), then the XR3-red with the longer length horizontally, now back to the XR3 shape but with the depression to clear the lock. I have shortened two pair of stags from XR3 red, to fit the new XR3's and hollowed out the clearance. Those same pair of grips are now on my Colt SAA. 44 Man
These are all the same two pair of grips made for the XR3-red.
On the XR3-red first
Then shortened and on a new XR3
Then on another 'New' Vaquero
Then on a pair of Gaucho's with a little more fitting.
Finally on the Colt SAA. All the same two sets of grips!