I think that the Mach IV is a wildcat from the 1950's that was used for match shooting. I don't know of any commercial ammo or rifles that were ever made. If you want 17 centerfire go with the 17 Remington.
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17 Mach IV ammo is commercially made by Cooper Ammunition. The point is mute now as I have decided on a .221 Fireball using 37 grain hollow points. Thanks for the response.
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