Well, if you want an inexpensive 22 revolver, you might look again at the Ruger Wrangler. As mentioned by someone above, the grip frame is zinc, but it looks like the most of the frame is aluminum; perhaps it won't have the issue with flame cutting like the Diamondback I linked too.
(The Wrangler isn't my kind of gun, but it appears to be better thought of than the Diamondback, I haven't shot either).
The Wrangler frame is machined from cast aluminum alloy, which is both lightweight and easy to manufacture. The barrel and cylinder are made from steel, of course, but the grip frame is cast from a zinc alloy.
https://www.gunsandammo.com/editorial/ruger-wrangler-review/364125
It's unlikely that the grip frame is actually made of "zinc." It's far more likely that it's made of Zamak, and probably Zamak 3. Zamak 3 is not junk metal like what is commonly referred to as "pot metal," which has no standard formulation and which has inconsistent properties. Zamak 3 has surprisingly good physical properties.
Zamak 3:Compressive strength: 60,000 psi
Ultimate tensile strength: 38,900 psi
Yield strength: 30,200 psi
Modulus of elasticity: 14,000,000 psi
Brinell hardness: 82 to 97 (sources vary)
4140 Steel:Compressive strength: 60,000 psi
Ultimate tensile strength: 95,000 psi
Yield strength: 60,200 psi
Modulus of elasticity: 30,000,000 psi
Brinell hardness: 197 (sources vary)
Zinc:Compressive strength: ??
Ultimate tensile strength: 13,150 psi
Yield strength: 10,800 psi
Modulus of elasticity: 10,208,000 psi
Brinell hardness: ??
Aluminum (6061): https://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA6061OCompressive strength: 14,900 psi
Ultimate tensile strength: 18,000 psi
Yield strength: 8,000 psi
Modulus of elasticity: 10,000,000 psi
Brinell hardness: 30
I'm not seeing a problem with Zamak
[Edit to correct Zamak mechanical properties]
