who knows of the heaviest .177 pellet?

[ballisticboy]

So is the very lightest 22 pellet going to have a flatter trajectory
than the very lightest .177 pellet?

The flattest trajectory to a first order is going to be with the lightest pellet which will give the highest muzzle velocity for a fixed muzzle energy. That in general will be a .177 pellet. The drag coefficient will make a difference but over 50 yards it is going to be very small. The lightest pellet will not necessarily have the worst wind response either so don't worry about that. The best pellet will be the one you can hit various targets at different unknown ranges first time with.

[delby52]

The flattest trajectory to a first order is going to be with the lightest pellet which will give the highest muzzle velocity for a fixed muzzle energy. That in general will be a .177 pellet. The drag coefficient will make a difference but over 50 yards it is going to be very small. The lightest pellet will not necessarily have the worst wind response either so don't worry about that. The best pellet will be the one you can hit various targets at different unknown ranges first time with.

So a .177 pellet will not always have the flattest path or lose it's energy quicker than a .22 pellet The old cal debate should be wide open! A chrono is now essential to judge performance of your riflle with a variety of pellets and calibres . I know that co2 air guns perform better higher energy with larger pellets due to the greater weight, is that the same with pcp and spring?