I ran it because shot 3 gun at the time and didn't want to reload for 40. If your just having fun it is ok. If you are trying to be really competitive it is a disadvantage except on steel stages. Sometimes it does save you a reload.
38 fits nice in a 40 rounder and I sometimes get carried away and pull the trigger faster than I should resulting in a couple extra shots on the targets for makeups.
Blue bullets 125TC with 3.3Grains of titegroup or Blue bullets 135TC with 3.1 grains of tite group.
The 125 shoots a little lighter but the 135 match my handgun load and feed better in the bullet feeder.