The misfires in the Browning BL-22 were caused by a locking plate that was no longer within the correct dimensions. This issue is well documented on this website.
At one point, I 3D printed a few test plates, which made it easy to measure and determine the proper dimensions needed to eliminate the excess play in the bolt.
You can print these plates yourself and fine-tune their size until the gap between the barrel and the bolt is completely eliminated.
https://www.tinkercad.com/things/hz5vcwNLIIX-browning-bl22-misfire-tests
