I was doing research in anticipation of building a light gun machine for the BasementArcade. I quickly came to a list of games that were compatible with the standard Happ light guns, but quickly realize there were some rare titles I would never find. A simple game called Bang! by Gaelco released in 1998 comes to mind. Anyway, during this research I also discovered this video, that seemed super interesting and solves the issue of playing those hard to find titles, on an actual arcade machine. This video, available to the left, shows MAME running on an arcade cabinet playing light games using Happ light guns. The video has a brief, blurry picture, showing a board called Usb2Gun that allow the interface of arcade guns to a PC, and give a path for a MAME base shooter using native arcade hardware. Although most of the games seem super playable, the video isn't clear enough to actually figure it out what this guy did to get the results he did. One this that was clear was he was using a game called America's Army by Global VR.
I made a mental note to look into this further, and put the term "American's Army" on my eBay saved search in hopes I could find some parts, or the actual game hardware that makes this possible, somewhere down the road.