I’m going to guess the chambers (at least one or two of them, which is all it would take) are lightly tapered from the front. this would allow the loaded round to drop in easily but the fired round would expand into the larger front portion and lock in the empty case. More reaming would probably not help until the whole length of the chamber got oversized. You can’t “ream it smaller.”

My vote goes to rechamber to 22 mag and look for a replacement in 22lr so you have two useful chamberings. Then again, it’s your money, so it’s your decision.

Froggie