To me, range is a combination of 3 things (assuming all other aspects of the gun have no problems):
1. heavy BBs - 0.28 or heavier. Yes they cost a bit more, but SO worth it.
2. Good tightbore barrel
3. good hopup
If you have those 3 elements in place, even a lot velocity gun will shoot ridiculous ranges and offer good accuracy. This is assuming that you have good airseal, consistant mechbox, etc...
__________________
|