Keyholing is usually referenced to the slr-104ur and the 5.45 round, and most members on the ak files forums dispel it as a myth unless your barrel is way out of spec to start. But I digress; I sent my 107ur and 104ur to Tim at Two Rivers Arms in Oklahoma. I had him do a little extra work but he did a great job. The turn around time was about 3 months as they are usually working on things, but we'll worth the wait.