Steel Challenge matches DO Allow rimfire rifle and pistols, as well as other pistol calibers. You stand in a shooting box and shoot at 5 steel plates on the clock. Shoot each setup (stages) 5 times in a row, the worst time is thrown out. It's best to have 5 magazines or at least some hi capacity mags for the rifle. All the folks at the matches are more than willing to help out new attendees.
Come out to the OKC Gun club on the 3rd Saturdays of the month and we'll get you started! You can also checkout some youtube videos of folks shooting Steel Challenge to see what it's like.