The main (& only) problem is getting it work in windows.
The timing/locating that was done by the original arcade hardware requires some extra hardware to be used for it to work in windows.
There's
supposed to be a board that does this, but no one here has tested it. It's possible to BYO, if you're
really good at electronic timing.

(Or you can try hacking the stuff out of other lightguns.)
Once it works accurately in windows, it'll work in mame.