Originally Posted by Protocall_Design

Most 38 Special die sets won't go down far enough for seating and crimping on Short Colt. Most people are using a 38/357 size die and 9mm for the rest of the dies.

To set seating depth from scratch, run the seating plug up so it is clear of the bullet when the case and bullet are all the way up. Then screw the plug down so it seats the bullet too high. Measure the overall cartridge length with a caliper. Keep seating the bullet a little deeper until the OAC length is what you want. Lock the seating plug at that depth.