To freeze the barrel (quickly, no overnight required), use a can of spray air (the stuff used for blowing dust off computer keyboards etc., from places like Staples etc.). Put the straw in the nozzle, turn the can upside down and blast the part of the barrel that fits into the receiver until it looks evenly frosty. That will shrink it enough that it will just slide in, with no difficulty at all.
I've used this method on all kinds of interference-fit applications, and it hasn't failed me yet. I did this with a roller bearing that had to be shrunk quite a bit to fit into a crankshaft - the bearing couldn't be driven in at all (it was .0017" bigger than the hole it had to go into). Shrunk it using this method, it slid in easily using only my (gloved) fingers.
This method cools to something like -200 degrees, vs. -4 or -5 in a freezer...
I've used this method on all kinds of interference-fit applications, and it hasn't failed me yet. I did this with a roller bearing that had to be shrunk quite a bit to fit into a crankshaft - the bearing couldn't be driven in at all (it was .0017" bigger than the hole it had to go into). Shrunk it using this method, it slid in easily using only my (gloved) fingers.
This method cools to something like -200 degrees, vs. -4 or -5 in a freezer...


















































