Eric, I've been reading the replies to your thread on ALR, and have to say that a lot of guys are giving you a lot of hasty advice. Personally, I think the problem is that the barrel wasn't inletted all the way down. That's really not too big of a deal, though.
You said there is 5/16" of web at the breech. That's a lot of extra meat in there. I'd drop it down to 1/8". That would make up 3/16". You can get back the other 1/16" by drilling the touch hole slightly below center. With the swamp on that barrel, you'll still have enough left for a 8-32 front lock bolt without getting into the barrel channel if you hug the barrel.
Is the lock plate now in the correct position fore and aft?