Every time you increase weight your fps lowers, but your BB tends to fly a little straighter. This isn't always the case. Accuracy can be affected by a number of things. General rule of thumb is a heavier round will fly straighter. But a gun with lower fps will eventually hit a wall. By that I mean that a higher weight BB will be too heavy to be effective. A higher fps gun will eventually run into an issue where a certain BB weight will be unstable, and won't fly straight. Almost any gun can handle a 0.25, or a 0.28 though. You can mitigate these issues by adding a longer barrel for flight stabilty, or a tighter bore to straighten out a lighter BB. Increasing or decreasing fps can also affect these things. Trying to find the right balance of power, range, and accuracy. A standard AEG combination seems to be a 6.01 tightbore with an m130 spring running a 0.28 round. But no two guns will react exactly the same. Also having a good spin put on the BB by a proper hopup assembly can help make a world of difference.
If you really want a better rundown of BB weight afflictions, talk to an "experienced" sniper. They are generally the best at finding that perfect balance. For a assault weapon the best way is to get your gun into the 400ish fps range with 0.20's. With a combination of spring power, good airseal, and barrel length versus bore. Then try a few BB weights to see what works for you. That way you won't have to overly change your gun after the fact.
Also remember that certain guns come with specific high end upgrade parts that are made to work well together. Companies like PDI, Laylax, Systema, RA Tech, and Guarder seem to put out dependable parts.
ďREALITY IS LIKE A STONE. TO MANY ITíS HARD AND COLD, THEY CANíT HUG IT OR EAT IT, IT ONLY FRUSTERATES THEM AND DOESNíT DO THEM MUCH GOOD. TO OTHERS ITíS STRONG AND DEPENDABLE, YOU CAN BUILD WITH IT, BUILD UPON IT, OR WORK WITH IT, ALSO USE IT TO SMASH PEOPLE IN THE FACE.Ē
Last edited by Ricochet; September 24th, 2011 at 10:42..