I shoot a 21 quite a bit for sporting and just completed shooting 200 rounds at a tournament last weekend. No malfunctions. The problem you described has never happened on any of my 21's. If the selector button function is crisp I would think you're bumping it with your finger during recoil. Maybe the stock l.o.p. is a bit too short for you and you're getting an exagerrated movement if the gun isn't fully against your shoulder when you pull the trigger on the right barrel. Incidentally my sporting 21 has Briley thinwalls and I always shoot the right barrel first, never thought much of the left barrel first concept. Silvers
