It all depends on the match, and if you are on the regular firing line, or shooting up in the Primitive range. Contact the NMLRA. You can join, and they will send you a shooting Program that described the various target events for the national matches. If you ask them, they can send you a brochure on their various targets( which are for sale so you can use them at your home range to practice). The Brochure should correlate to the targets listed for each shooting match.
On the primitive range, they shoot a lot at metal bang plates, of difference sizes and shapes. Those will NOT be listed in the brochure on targets. Ask about them. The dimensions are no secret, and any member can get that information. What is different than on most ranges is that on the primitive range, don't be surprised to have to be shooting UP HILL at a target that may be from 25-50 yards from you. Some paper targets are shot in the smoothbore primitive shooting courses, as well as the bangplates. Bangplate targets are scored, hit or miss, to keep it simple, and shooters moving from one station to the next. New courses are often added each year, and sometimes, older courses are changed because of some change in the range terrain. But, generally, once a match is set up, it does not change, so that there is continuity in judging past scores with current scores to determine the match record holders.