Remington ACR is better bc if you using Hollow Point or HP you can 2 shot zombies on head except Charge in LGCY Stories, Hunter, Smoker and Witch Remington is an corporation where ACR produced
Aks-74u is actually op though, I'm speed running BC of my op gun and my best time is under 7- mins (BC of using Fmj holy dam it's op and low recoil + can ez pc penetrate through high hordes)
Ever since FMJ got nerfed it's crap except for the HK21 which the gun itself does the same damage either to the head or body. Extra ammo is mostly good for assault rifles so you can keep firing for longer for more damage over time and not have to reload every 4 seconds. HP is very good on SMG's because it actually give's 20% damage boost on SMG's and HP gives 10% damage boost on other weapons.
I don't know which ak you're talking about but let's say it's ak 47. Ak 47 = high damage, but slow reload time, low rpm and high recoil. Scar = acceptable damage, very fast reload time but high recoil and low rpm In my opinion i prefer scar
