It made me mad that H&R would make two types of SB2 frames and I really hate hearing "You can't fit rifle barrels to them".
I've never seen anything you couldn't do given enough time and money....so, I took my 30/06 barrel (which fit fine except for the slightly wider cradle) and put a little accuraglass inside the cradle, hit the barrel hard with boiled soap as a release agent, and put the barrel in. I used Accraglas because it comes out easily with a little heat and I have other plans for the slug gun.
Worked fine. I fired a half dozen moderate handloads through it and it didn't loosen up at all. Then i heated the Accraglass (not the frame) and peeled it out, clean as could be.
I'm not sure why one would want to do that, unless they just got a great deal on a shotgun receiver, but it can be done. I have a sneakin suspecion that treatment might help an inaccurate rifle, but I'll leave that for another day.
One other thing, there wasn't any problem with the larger firing pin. That was a crap shoot. Sometimes they work and sometimes they don't. I've put rifle barrels on pumo shotguns and had mixed results with the pins. You may need to drill the breech face, install a bushing and make a new pin.
