You can shoot the course with whatever you have. Given the current cost of ammo, and the training being mostly done at 25 meters, .22LR is the way to go anyway. If you bring a rifle of centerfire caliber, you will do better with one that will take strippers or magazines. You will have to work more with a boltie, but it can be done. I have seen Mosin's, K98's, K31's, and Enfields.
I have built up 2 10/22's, one for me, and one for my son, just for practice and for doing Appleseeds. These have the Tech Sights that are selling like hotcakes. You can run them with a scope if you wish. You can use whatever you have, just make sure you have a sling on it. The M1 Garand/M14 Web sling is the preferred one for them, but I use the leather Match one as I prefer it.
-Bidah