My advice is to stick with a shell that works for you. According to the NSCA rule book, for sporting clays, if you are shooting 12-gauge lead shot, you are limited to a maximum of 1 1/8-ounce load. Shot size must be between 7 1/2 and 9. For steel shot, shot size of up to 6 is permitted. When shooting FITASC, the maximum permitted load is 1 ounce (28 grams) and spreader shells are not permitted. For more on ammunition rules, see the 2017 NSCA Rule Book: Section IV-E-4 for sporting clays and Chapter 7 for FITASC.