.22 is easy to do, with some kits being primarily SS, still lightweight, and still roughly $100-120.
.45 I've seen referred to as challenging by guys with double digit centerfire Form 1 cans. It's synonymous with building a 1911, except the ATF is interested in any potential missteps or replacement parts. Possible, just not something to dive in without wandering into a Form 1 board and learning a lot first.
I've got a few interesting posts soon to come on Form 1 cans though. Now remember, this is NFA-land we are talking about- soon means within a month or two!
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