Doesn't calibrating in the games service menu correct for this?
(only moving the gun around the 4:3 window when calibrating)
I didn't spend a lot of time trying different titles, but I tried this once and saw an odd calibration. However, I was able to get it to work properly using "trick" calibration, which for those who don't already know, means not shooting at the centers of the calibration targets, rather offsetting aim during the games calibration setup to compensate for what the gun is actually doing in the game. After that, there was no problem, but it can take a few tries to get it right if one isn't used to it from, say, messing with wonky touchscreens
Well, I me too made it work finally, not easilly and to be honest , not exactly sure what has fix it. Like a lot of time, made many things to fix a issue and not sure what fix what. But my problem was more about exactly the initial post/question... " This seems to cause the aim to be off because windows sees the edge of the screen at the actual edgs whereas MAME has a smaller window".
In my case, I first change MAME from 1.86 to 2.39b, problem start. Roms no more compatible. I fix it. But the 2.39b have more option for video overall...I also recalibrate. Oh my god, simple on paper, not in reality. I was forgetten all the trouble where the middle calibration don't accept it. Another couple of hours my life loss
. But I made it work by having two IR bar on top of each other to make the job.
In between, many mame options changes..., also try changing my video resolution, IR gain, etc...
Anyway, in short, this hobby is full of fun
.