I have a .243 barrel that I am fitting to my frame. I cannot keep it from popping open and it's getting very irritating. I've been working on the locking lug a little at a time and blackening it so I can see how it fits since I don't want to go too far. It looks good, but still opens at the range. I looked on the FAQ's and cannot find the information on fixing this.
I wish that H&R (Remington) would just tighten up the tolerances to make the barrels swapable between frames. For a few more $ it wouold be worth it. If Remington makes the frames and barrels on its own machines this just might be possible. Of course the design just might not lend itself to interchangibility.