Next, go to the the local rifle range on a clear, calm day and set up a suitable target at 50 yards. Shoot from a bench using a solid rest. Fire five fouling shots first, then begin your record strings. Take your time and make each shot count. Fire at least five groups of five shots each, then measure the extreme spread of each group and average the results (add them together then divide by five). Clean the bore of your rifle thoroughly and repeat the process with other brands and/or loads. After you identify one or two brands which are superior, retest only using those.
Once you have identified the brand and load your rifle prefers, conduct similar tests with different lot numbers from the selected load to determine which works best. Prudent competitors then purchase ammunition from that lot in quantity to assure a future supply.
Learn about how .22 LR cartridges are made