I haven't really figured out a reason for it and I've never really found a discussion of it but in single player the aim will get way off sometimes. Particularly noticeable with the Sniper Mauser rifle. Can be aiming one place and the bullet is going a completely different spot. Anyone know the deal with that? Is it just random and you have to deal with? I've had this on multiple computers and an old cd install as well as Steam.

It's been years since I played single player but I never noticed anything off on the aim.

Use the scope

That's the most noticeable situation where this problem presents itself.

If you're standing/crouching still the shot should go right above the vertical reticle. Don't go around jerking the mouse when you shoot either, set your mouse sensitivity lower if you suspect that's a potential issue

I can't remember single player much at all. Is there a green bar that expands/contracts as you're aiming down the scope and move the mouse?

This is entirely my point. And let me just say I've beat the single player mode entirely a number of times on "I Am Death, Incarnate" so I totally understand the mechanics of what you're talking about. Literally, standing or crouching still, fully aimed, sniper scope, take the shot at a wall "50 feet" away and the bullet will miss by a couple feet and it will miss in the same spot each shot. I have to do that sometimes so I know where the bullet is going so I can properly aim at the bad guys. It changes seemingly randomly but not every shot. Like a whole level will be like that, or half a level or whatever. And like I said, multiple computers, both Steam and disc installs, etc. Its not my setup.

That is strange. Does it work normally in WolfMP? You could try copying the config file from main folder of MP to SP, just make a backup in case.

That I don't know. Probably been 15 years since I've done any MP.

It happens to me at the beginning of the baseout level when you're firing toward the 12 Nazis running toward the MG-42, and also in the SWF level. It's not just you, it's a bug in the SP campaign.