I began having problems with about every fifth round failing to clear the ejection port recently. At first I thought it was ammo related but I have tried a variety of 40 grain rounds including CCI minimags which have ALWAYS worked in my other 22 caliber guns. The spent round is caught and partially crushed by the bolt as it closes. Great practice for clearing stove pipe stoppage but very frustrating. On dropping the mag and clearing the stove pipe the chamber has a new round in place, so the bolt seems to me to have come forward too soon, but it doesn't happen with every round. Is there a fix for this?