Well, the Boreteck not withstanding,
you have a Steel barrel
In teh steel barrel you have
1) a cotton patch
2) some wood dowling
Since you think the barrel is a goner, you should go to a metal supply shop, get a piece of steel rod that will fit the .223, then chamfer the end and hammer the piss out of it, after all, what do you have to lose?
or...
Take it to a machine shop, ask them to chuck the barrel end in a lathe and using a long drill bit, ream out the wood from the muzzel end. What do you have to lose?
or...
Go to Home Depot, in the electrical section are long drill bits for running wire. Mine sells a very small diameter drill bit that will fit a .223. Chuck it up and go to town! What do you have to lose?
Putting any fluids in it has done nothing but swell the wood, so by now it's hammer, drill or die tryin.