The Ransom Rest brings the frame back to the same place every time. The slide and barrel have to return to the same place on the frame after each shot to be able to use the rest for accuracy testing. As long as the barrel and slide return to each other after each shot then accuracy potential is better when holding the gun in your hands. This is why, when accurizing a semi-auto pistol, barrel lock up in the slide is more important than slide to frame fit. Revolvers do not have this problem as the barrel and sights are always in the same place.