I agree with those who said this does not appear to be much of a valid test. Compare the subject work with Steven Boelter's (2005) "The Rifleman's Guide to Rimfire Ammunition". Boelter used 8 or 10 rifles and shot up more than 32,000 rounds of ammunition. And some of his work has been criticized as incomplete. Boelter's coverage of 22 Shorts was minimal. I'm playing with an evaluation of Shorts. Have shot up 5,000 rounds in 4 rifles so far and I'm just getting started.