I noticed a long time ago that some guns don't seem to have the same FOVs, even within the same category. Today, I've tried to do a short comparison. I picked the guns up and pointed them at a wall, standing still, while switching back and forth between weapons and looking at reference points on the wall to compare. Some of these are different by mere pixels. And they're all with ironsights, or with their default scopes. Tested on separate machines. @DPI Wizard, if you have the will and patience can you please confirm? Could you potentially update the calculator in some way? There are so many different values though, so I'm not sure how....
Zoom level from largest to smallest:
winchester (SR) > crossbow > m79 smoke launcher (sidearm) > panzerfaust > P90 (AR) > MK14 (DMR) > mini (DMR) > MG3 (LMG) > MK47 (AR)> Other AR/SR/LMG > Other DMR > G36C AR > shotguns > SMG > PP Bizon (SMG) > Tommy (SMG)/Skorpion (sidearm) > r45 (sidearm) > r1895 (sidearm) > sidearms
No idea about the flare gun.
Another fun part comes when you attach scopes. When I noticed the MG3 FOV changed with a red dot but not some of the other guns... oh boy. So many variables.