There's no change as far as I can tell with the speed of the firing for the Assault Gun.

For some reason, the Assault Gun seems to shoot at the same speed as the Doom Chaingun... which should not be the case. IIRC, the Assault Gun shoots faster than the Doom Chaingun.

I don't have any means to verify that this is the case... so until we can verify this as the right behavior it stays like it is now.

It's probably not that hard to obtain the game and run it under DOSBox. Otherwise, ZDoom has a pretty close approximation.

Checking against ZDoom, I see that we are using the same values for frame durations, so the speed should be the same, which makes this even more strange... I'll leave it open for further investigation.

Is it just possible that the sound (the shots themselves) is simply just slower?

Frame durations were extracted from original exe so they are correct.

Could you please try the latest SVN and report how firing the weapon feels? There were some small improvements in performance, which I suspect had something to do with the "feeling" of firing weapons.