SA did not make "drill rifles" as such. They made fully-functional infantry rifles and carbines. As such it should be perfectly shootable.

However, one cannot be sure what parts might have been put onto such a rifle, by others, when said rifle was to be used for that purpose. There is also the consideration that the plating process could have somehow damaged the metal, though that is probably unlikely. And lastly, if still "as made" (NOT converted to an 1896) there is the issue of value. Unaltered M1892s are scarce if not rare, and their stocks are fragile at the wrist.