I had a CSMC M21 that went off face after several years @ sporting clays shooting (bolt adjustment would not compensate) so I attached a .002" mild steel shim to the hook w/ Permatex Sleeve retainer (available @ NAPPA & is used for securing valve guides in aluminum cylinder heads).
I shot it for several more years @ sporting clays w/ the shim in place before I sent it to Dennis Potter to do a proper repair by replacing the joint pin but I could have kept shooting it w/the shim.
I don't see any downside to the shim repair & it is relatively easy to do, reverseable & cost effective on a low end shotgun that doesn't warrant rejointing.
