[LUTNIT]

Barrel length mostly determines accuracy at any given range
FPS mostly determines range

I said MOSTLY as there is some overlap. A longer barreled gun can APPEAR to shoot farther because it has a longer EFFECTIVE range as it can have much tighter groupings at any given range even though the higher FPS gun will get the BB's farther out there. Ideally you want a 370-390fps gun with a barrel at least 450mm long.

Also hopup design has to go into range, I can outrange a KJW M700 shooting 550fps with my 320fps STAR M60E4, no idea how or why but it can.

An AK has a 455mm inner on average, an M4 363mm (damn I knew those off the top of my head, I need a break from gun work...) Really an AK is a good platform for a medium to long range weapon. If its a Kraken I recommend getting a tightbore inner, TM hopup unit, Guarder clear hopup rubber, metal bushings, bearing spring guide, and an upgraded spring (a Prometheus Ms110 should bring you to 370-390fps with that setup if properly installed.)

If you want a bullpup a FAMAS is out of the question as its ver.1 mechbox can't handle much past stock sub300fps. An AUG is nice but aren't too common and I have heard a lot of problems with them breaking parts but have no experience. A full length L85A2 has an M16 length inner but is the size of an M4A1 and can take armalite mags. Has a quick change spring to go from close quarters games to field games in under 10 minutes. They are known to have some issues with battery storage as there isn't much room for one and you probably want a large battery to turn over 400fps upgrades.