Don't forget that in theory the further the bullet travels, the less damage impact it produces. Drag reduces energy, and the longer a bullet travels, the speed is reduced. Speed, not mass is the big factor here.
Also, don't forget that these settings in AH are in YARDS...not feet. Real convergence in F4U's was done in feet and the optimal convergence was 1000 feet. (The closest you can get to 1000 feet in AH is 325 yards (975 feet). (Real Gunsights were marked off in MILS (latin for 1,000th)
Ideally, you want all the bullets getting to the same square foot at the same time. The F4U-1D could deliver approximately 80 .50 caliber bullets per second at convergence. (pretty impressive...thats about 5 lbs of lead =)
After the bullets converge, they cross path and continue traveling. At twice the distance of the convergence point, (if 300 yards, then it would be 600, etc.) the bullets would have 2 impact areas the distance of the guns on your wings. In other words, if the plane you were shooting at was say 500 feet away and you were at his 6 o'clock, the bullets would cross and strike both wings.
I only fly Corsairs and my convergence is all 6 guns at 300 yards. (I would do 325 yards, but enemy distance mark-off goes in 100 yard increments). I start shooting at and enemy fighter at about 500-600 yards and a bomber at 600-1000 yards.
I've had quit a bit of success with this. Good luck to you Sir!
:aok