Hi Pharaoh2

I believe you could drill/tap a vaquero, but why bother? You could never give it away in the future (ok, you could give it away) and are kind of " killing" it for its most popular use, CAS with .38. I wouldn' t even think of taking a small bore single action hunting, and .357 is illegal for big game hunting in many states anyway.

I think you would be better off selling it and getting something more appropriate.