Abot these weapons

Hi,i have in my inventory several guns,some of them:Ak 47,Scar Light,G36K and AK 47 Camo(i love it,but i only have a few days on it ,but it was my luckiest crate in all time,one very good gun+1000GP+10000GP ),and i want to ask your oppinion about where do they fit the most? On what type of gameplay? (Where do they perform better)
Seriously,i need an advice

Also,i was wondering on a possible new gun,to use it in more than one gameplaymode.

(Abot,i wanted to say about)