Or though not as glamorous, you can try the economy solution. I was in a similar predicament and boiled a factory synthetic stock in a propane turkey fryer (5 or6 gal I think) filled with water. I got it boiling good and then put the fore end down in the pot. The plastic doesn't get really soft but softens up some (enough to do the job) after about 15 or 20 minutes or maybe a little longer. Then with gloves on I forced a 1" wooden dowel (big fat broom handle) down into the barrel channel and secured it with duct tape till it cooled. once it cooled it retained this shape. I did have to relieve the barrel channel just a little at the tip to accommodate the heavier barrel. This allowed me to put the heavy fluted threaded barrel off of one of the older model 10BAs onto an old 110 sporter without spending any cash. Plenty of clearance and it has worked well for the last 8 or 9 years.
I may have been accused of "redneck engineering" a time or two but it looks factory and most importantly it works. LOL Sorry for the crappy pic.but it's the only one I have of this setup.