> The Handi Rifle seems to me to be a prime candidate for aftermarket parts.

One would think, but the only datum I have seems to indicate that Marlin/H&R discourage it. For the life of me, I can't imagine why! Anyway, JD Jones of SSK Industries told me he's tried to buy barrel blanks and they refuse to sell them. He said he could make them, but it would be too expensive to be commercially viable.