Originally Posted by PT-92
When I was researching which 1911-22 plinker gun to get, I really found two that were unique in that the offered an all-metal frame/slide and those were the RIA and CZ (though the CZ isn't a 1911-22 model so to speak but still very pretty and durably reliable). Almost all of the other offerings in the .22lr semi market (S&W M&P, GSG/SIG, Browning, Colt and even the Ruger SR22 use cheaper types of metallic base material on their respective slides (some people refer to Zamak slides as "pot-metal" for example).
It appears you overlooked the Kimber Rimfire (yes, they sell a complete pistol as well as a .22 conversion). It's all aluminum alloy -- no Zamak.