Darkstar 2520 wrote:could a m4 inner barrel have as much range as a m16
Generally, no.
An M4 length barrel is 363mm long.
An M16 length barrel is 509mm long.
The longer barrel is going to give you more range and accuracy, but if you want that out of an M4, you can run a 509mm inner barrel through a suppressor to get the same result, although, this means you have to go out and buy the parts instead of just getting the M16 with the longer barrel at no extra cost, but that's your decision based on what you want your AEG to look like.