I recently bought a 219 rechambered from 25/20 to 25/35 which came with an extra barrel in 20 gauge. Actually, the spare barrel wasn't for the 219 at all and is stamped Model 220 but it fits mine like a glove. I since have purchased an additional Model 220 shotgun barrel in 410 and a Model 219 barrel in 30-30 and they all lock up fine and fire safely. Check the ejectors and see if they're bottoming when you close the action. This could be causing a problem also.