Hi MSP RET:
The way the Handi's are built there are no effective side movement bearing surfaces so I bed the lug/barrel in eight locations to at least dampen out lateral vibrations which can adversely affect accuracy.
The bedding material is one part resin, one part hardener and one part aluminum powder.
Before I go any further I check the clearances with eight small bits of Plasticine put at each of the eight locations. I then assemble the barrel and close. When removed the crushed Plasticine tells me how much clearance exists at all eight locations. This information I use to gauge how much epoxy mixture to apply. I clean up and degrease thoroughly, add three layers of masking tape on the underside of the lug to provide clearance when removed after the job is done and then spray my barrel/lug area with Rust-Guard-It so I can get the assembly apart when set. I then apply the epoxy sparingly at the eight locations and firmly snap the barrel in place.
I think the epoxy can easily be chiseled off later if you decide to fit another barrel. It could then be steel-wooled clean.
Hope this helps.
Mc