Originally Posted by m102404
If the mechboxes are basically shooting the same (the M16 uses a full cylinder, where as the M4 uses a ported cylinder....but ignore that for now)...the M16 will deliver more accuracy at range. That means your effective range (you hit what you're aiming at) increases.
Originally Posted by ybrik
greater range for an m-16 with a 509mm inner barrel length compared to a much shorter 363mm barrel length of a standard m4. But you could still install a 509mm inner barrel to a standard m4 and a suppressor to cover the excess sticking out of the outer barrel.
Haha, I'm going to keep having to debate this.
longer barrel != more accurate
As far as stability and acceleration time are concerned, those are taken care of by porting the cylinder and are less of a factor in airsoft than with powderburners, air rifles, or paintball because the volume of propellant gas in airsoft is comparatively small.
This means it's easy to supply enough air to a projectile in a full length barrel.
Bigger factors are power consistency, part consistency, stiffness, and lock/dwell time.
As far as long vs short:
power consistency is pretty much the same for stock AEGs
part consistency is likely to be better for shorter barrels
(but hop consistency, which is overall more important, is the same)
stiffness is MUCH better for shorter barrels
lock time is about the same for AEGs using similar electrical setups and mechboxes
dwell time (at the same velocity) is MUCH better for shorter barrels
Adding any kind of optic negates any advantage of a longer sight radius.
The 4" change between an M4 and an M16 is going to make effectively ZERO difference on the performance of the rifle. It will make a HUGE difference on how easy the rifle is to handle though, especially if you're smaller framed.