Last summer I bought my first Handi in .308 and being a tinkerer started looking for info and discovered the mother lode here. The idea of having extra barrels appealed to me, so I managed to obtain three from the classified ads on this site. Having read the FAQ's on barrel fitting I was comfortable with fitting my own and it seemed a LOT better than sending my receiver in for fitting.
I acquired a .44 mag, a .223 and a .30-06 (in which I installed an adapter to 7.62 x 39). I was really hoping I wouldn't have to shim any of the barrels and praise the Lord, each barrel was too tight and wouldn't close. A little judicious sanding on the pivot lug, squaring the face of one and a bit of stoning on the latch shelf and every one is a nice tight fit.
The .223 barrel was the last one I fitted and when it wouldn't go, an inspection of the pivot lug revealed it had been built up with JB weld. OH NO! The seller said the barrel was untouched. Now it looked like I had ended up with someone's botched job. First thing was to remove the JB weld which came off surprising easily. The big surprise was when I checked it for fit before continuing... It fit up perfectly! No shimming, no sanding... perfect!
So, as they say, all's well that ends well!