A lot depends on how much you have to build up. Gluing in a dowel then gouging it out to the proper diameter/depth is an option if there's a lot of slop to take up. If you use the Acraglass kit from Brownells or something similar you can wind up with a very nice, smooth junction between the stock and the barrel. http://www.brownells.com/gunsmith-tools-supplies/stock-work-finishing/stock-bedding-adhesives/acraglas--prod1033.aspxThere are videos on Youtube that show the process of bedding a barrel/action with Acraglass and such.