I had a Magnum Research 17HMR which was super accurate, BUT, also had 5 case head seperations. One of them destroyed a magazine, the another ruined an extractor. The last one spit pices of brass into my biddies hand and side of his face which was DEF THE LAST STRAW, as I returned it to Magnum Research and got my money back. Long story short, 17 HMR just doesn't work in a semi auto 10/22 platform. Volquartsen has made it work if your in the market for a $2,000 17hmr.