W. H. B. Smith & his argument for the superiority of CO2 rifles

[eyebull]

I've never read any of Smith's works, but how does he argue the superiority of CO2 over air?
Surely with the limitations of how CO2 works as a propellant, it can never offer the same levels of performance as compressed air? Hence there are no FAC rated CO2 rifles, but there's a profusion of air powered ones.

Though the invention of PCP predates CO2 by some margin, I don't think PCPs were commonly available at the time. Even if they were, the need for an expensive scuba tank as opposed to relatively commonplace CO2 tanks, and the relative expense of the powerplants (CO2 operates at a much lower pressure and is somewhat self-regulating, thus cheaper than PCP) would have bolstered his argument, not negated it.