I'm still new to GSSF matches and am confused about what category a G21C would be eligible for. On the match registration form the 21C only shows up in the 'amateur and master competition' category. But in a recent email I received from the GSSF it says "Major Sub is now Heavy Metal. You can shoot any 10mm or .45 caliber GLOCK in the division." So can I enter Heavy Metal with a G21C? Thanks!