Recoil Modifiers.
Certain categories of weapons have increased recoil modifiers. Every time one of these weapons would take a penalty for recoil (before compensation is applied) these weapons suffer an increase to those modifiers. This replaces the standard rules for heavy weapons suffering double recoil modifiers.
Heavy pistols an assault rifles increase recoil by 1; MMGs, shotguns, sporting rifles, and sniper rifles increase modifiers by 2; HMGs increase modifiers by 3; and Assault Cannons increase modifiers by 4.
A few weapons stand as exceptions: the Ingram Supermach gains 1 free point of recoil compensation, the Ares HVAR does as well. The RugerSuper Warhawk, the PJSS Elephant Rifle, and the Barrett Model 121 all have another 1 added to their modifiers.
Damage and AP
With the exception of the PJSS Elephant Rifle, all sport rifles have their damage changed to 6P and their AP to -3. With the exception of the Barrett Model 121, all sniper rifles are changed to 6P and AP -2. The Barrett Model 121 is changed to 7P and -3 AP. This brings the sniper rifles in line with the MMG rounds that they commonly use, makes the sport rifles slightly more powerful than most sniper rifles (which is commonly the case in real life), and puts the Barrett Model 121 in line with the HMGs. This also puts the Model 121 below the Thunderstruck Gauss Rifle in power. I'm personally electing to ignore the errata for the Gauss Rifle.
When I feel like typing more, I may add more changes, but these are all I care to do for now.