bullet trajectory's and flight path?

True. Given that there are no obstructions in a flight path. If you could drop a rock at the same time as a bullet leaves the barrel they would both hit the ground at the same time.

Assuming two bullets are fired at the same muzzle velocity, have the same ballistic coefficient, are of different weights and are traveling through the same atmosphere and affected by the same force of gravity.

The bullet with the lesser mass should slow down more quickly than the heavier bullet while they both encounter the same air resistance. This is because momentum is mass multiplied by the velocity.

The greater mass will start with a higher muzzle energy (momentum) and air resistance will reduce the velocity of the lighter bullet more quickly.

So in your scenario of two bullets having the same B.C. and the same muzzle velocity but different weights, the heavier bullet should be able to travel farther through the air before impacting the ground.

In actual practice, this doesn't normally happen. The heavier bullets are often traveling slower than the lighter bullets when exiting the muzzle of a firearm. A .308 Winchester cartridge loaded with a 150grain bullet usually generates a higher muzzle velocity than a .308 Winchester cartridge loaded with a 180 grain bullet. Often the ballistic coefficients are different too. This is why the ballistics & trajectory formulas are written to include several variables.

If the weight is different then your statement "All things being equal" is not true. But Physically it cannot be true because the coeffeciency has to be different because same diameter - different weight forces the 'package' to be longer.

Due to the velocity lose of a longer and heavier projectile cause by wind drag, even though the two projectiles will remain in flight the same time element, the 165 will strike further away due to it's retained velocity. This also assumes that the two rifles are fired at the same angle. If they are fired as sighted in at say, a 200 yards bullseye the 220 grain will travel for a longer 'time' due to the fact that it attained a higher degree of angle or elevation so it will have been 'dropped' from a higher distance. But it will still not travel as far since the higher angle is also a shorter arch.

The weight difference will change everything, not because of gravity, but because the bullets, all things being equal, will have different muzzle velocity. The heavier bullet will be slower out of the gates and the lighter one will be faster. Now look down range and the heavier bullet will have retained more of its velocity than the lighter one. So if you set the muzzle velocity to be the same, the heavier bullet will have a higher down range trajectory than the lighter one because it will have a higher momentum and energy. The effect of gravity is the same on both bullets, but the initial force that drove it out of the barrel would need to be different for both bullets to have the same initial velocity.

You can not have the same ballistics for the two if you have different weights. By the very nature of the ballistics, the heavier bullet will have to either be higher mid range or be going faster at the muzzle to hit the same point, hence the ballistics are different.

Nice Try.

The effect of gravity is a ratio of force:mass - it is totally dependend on the mass. If I follow your logic - then my F-250 truck would have the same gas mileage with one driver as it would with 6 people and 1 ton of bricks as cargo.

You will find trajector tables, and, all the math behind it - in Sierra's handloading guide. You can pick up a used one at a book store for $1 if you do not handload and just want the table and math.

Hope this helps

Your question is somewhat vague. But all things being equal except for weight of the projectile, the heavier bullet will have more drop at longer ranges. it will also be a little slower due to it's heavier weight.

The MAIN force that keeps the bullet stable is the gyroscopic force. Those other forces only have effect in extreme conditions, like high cross winds.

if you go to the different ammo manufacturers website they will have ballistics tables that will give you the trajectories and velocities

winchester, remington, federal, fiocchi, speer... i like remington's best

you can not have the same velocity or b.c. if all other things are equal! caliber size or powder charge would have to be increased or decreased. also gravity would be different on bullets of different weight so, no!