I've had quite a few of those older "first" model 4 and 5 digit frames. It usually isn't the locking bolt/s that cause the problem but rather interference between the inside of trigger guard housing and the bottom of the barrel lug under the hinge pin hole. If, with barrel attached you can't squeeze up on the trigger guard thats most likely the problem. The newer barrels lugs are usually a bit thicker under the hinge pin hole cutout. Only way to eliminate the problem with all barrels would be the factory easy open conversion, but then you'll lose the cool looking original trigger guard and I believe they'll change the hammer as well. No way I'd do that to an early 4 digit frame. In my case I wanted a Reeder custom octagon barrel to go on my frame so I "inked" the bottom of the barrel lug and removed a VERY small amount of metal at a time until the interference was gone. I was perplexed over this and none of the custom barrel makers could help or knew how to correct until I contacted Mike **cencsored word ? ***. No matter what anyone thinks of him, he knows T/C's.
