When I took my class, there was an old lady taking her course and she couldn't pull the trigger or the hammer back on her .38 special, so the instructor went and got her a .22 to qualify with. That left a comforting feeling with everyone in our class knowing she was 50 rounds away from carrying a gun she couldn't even fire.
Given the way our permits are set up (semi, revolver, derringer), any instructor worth his salt should strongly suggest the students use a semi.