'switchbarrel-itis' is fun for a while, but I found that it required trips to the range to be SURE any newly assembled rifle WAS sighted in, reguardless of how you set it up and 'supposed to be' sighted in. For me there is no shortcut to actually SHOOTING the rifle to be sure, before risking a shot at game. Collimators can get you really close but not what I consider 'for sure' especially if long range game shots are possible.
If I had not made several switch barrel bolt action rifles on my own lathe and friend's lathes [metric], and tinkered with them a lot, I probably would still have to build one or more switch barrel rigs just to see what they were all about. HOWEVER, after having them for many years I believe a READY TO GO rifle is much better to have. As I get older I just don't have as much time to play 'musical barrels and scopes' as I used to. Too much fishing and hunting [I mostly bow hunt now] to do. I don't want several 'partial guns' around that will need some tinkering and a trip to the range before they are ASSURED 'ready'.
I also had maybe a dozen Handi rifles through the years and sent the receivers in for factory fitted extra barrels. It was fun and I wanted to do it, but there came a time when I said "ok, enough of that, I want 'ready to go' rifles around me now".
AND, Handi rifles are so inexpensive.....no better reason to have as many as you can afford around in COMPLETE 'ready to go' form!