Hi
Easy fix...Call T/C and get the "grommets". They simply slide into the dovetail. If they are tight you may need to tap them in,or if they are loose you may need to tap the edge of the dovetail cut in your barrel. When you bend the edge "Slightly" it tightens the cut that the "grommet" goes into. You want them to be a little tight, so they do not fall out ...By the way They are called dovetail lock...T/C service number maybe 603-332-2441 They are also being sold on Ebay
Good luck
jim