At PSA only non magnum pistols and pistol-caliber carbines are used for shooting steel. The game is to knock down all the steel targets in the fastest time possible.
Although this is a game of speed, the Sunday 22 Steel Shoots are fun way to get the .22LR out and do some rapid fire shooting. For the more serious competitor, the PSA Rimfire Challenge is a more structured competition where time is kept and compared against other competitors.
Common rifles used in these competitions are the Ruger 10/22, Smith and Wesson M&P 15-22, or AR-15 rifles with 22LR conversion. You will want to have at least three 25 round magazines to shoot this game and enough .22LR ammo to get you through the day.