Shear strength of those pins are in the thousands of pounds, I don't know why you are afraid of pinning the barrel in, just put the new barrel in place, mark the pin locations, file a slightly under sized slot across the barrel where the pins go, then drill new pin holes and replace the pins with some a little over sized, it isn't anything that can't be done on a drill press. Steel pins will beat glue any day, and if you hose it up you just take the pins out and try again. Larry