A good SASS club will often allow you to experiment with different things, my local club runs both a Military class for we GAF types, and a WB class in their regular monthly matchs, as well as letting me use their range for my annual GAF match.
In addition, you may have a modern 2 or 3 gun action match in the area, the guys with Glocks and AR-15s. They often either have a class for older weapons, or simply welcome you to try their game with your weapons. I read the publication of the Grarand Collector Association recently, where a member went to a modern combat match with a Garand and 1911, had a grand time and finished middle of the pack.