The locking bolts on the barrel lug engage a "shelf" on the frame....have seen a few instances where a burr or sharp edge on the leading edge of the frame recess/shelf can prevent a solid lockup.

additionally, make sure your barrels are stepped lug and NOT early flat bottom lug barrels. Early flat lug barrels like the one below do not have the 1/8" "step" on the barrel lug....even changing the locking bolts on this style to a 2 pc bolt may not allow lockup on later frames.

[Linked Image]

Stepped lug style:

[Linked Image]

light stoning/beveling of forward edge of the locking bolts can sometimes allow for a lockup, but if the frame recess is out of specs, sounds like a trip back to TC is warranted.










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