The Fitment was extremely tight. Lillian put the barrel in the freezer, I but the receiver in the oven on 250 for 30 min. One expanded, one contracted, & we were able to tap them together with a rubber mallet and a little anti seize lubricant.
You can see here the hot receiver thawing the frost from the barrel.
BrooksHouse 
Must be nice to be smart! Awesome!