These are two AR-like semi-auto shotguns that are categorized as "civilian" shotguns in the US.
Standard Manufacturing's SKO-12: Holds 6 rounds per magazine, with a slower fire rate and tighter spread. Personally, I really like its design, except for the fact the model is a bit low poly. Plus I nick a Russian sight and stick it on top of the gun not very American.
Rock Island Armory VR80: Holds 10 rounds with an extended magazine, it has a faster fire rate and more effective range. But also with slightly lower damage and wider spread...yeah it doesn't really make sense. This design is rather American, I must say. Except for the fact it looks a bit "unconventional" compared to the standard AR-15 style.