The only Gun i use is the SD. It doesn't matter what map, As long as you know where to aim. IW, M-14, M4A1SD....It's still a one shot one kill. Just as long as you hit em in the HEad. All guns are equal in my opinion. (excluding the M203)
Well that's a good way too look at it.....It is just a lot harder to get a headshot with some guns!
i use the m4-sd in big maps but in small close quarters combat i use the hk5sd-that gun owns with acuracy and fire rate and i dont know why but i always shoot the head first with it lol