A 7mm Rem Mag drops about 32” to 50” at 500 yards, depending on the exact load you're shooting.

M855 Green Tip Ballistics. On average, M855 pushes a 62-grain 5.56 projectile at roughly 3,020 feet per second (fps). This is heavier than M193 with 7 grains of the weight being taken up by a steel “penetrator” at the tip. This tip's purpose was to allow the FN Minimi to be able to pierce steel helmets at distance.

The 350 Legend Muzzle velocity ranges from 2,200 fps to 2,600 fps, but suppressed rounds leave the barrel at speeds as low as 1,050 fps. The speeds at the muzzle vary with the bullet's weight, the rifle's barrel length, and the gunpowder, among other variables.

Take the expression for the traveled horizontal distance: x = sin(2θ) × v²/g . Differentiate the expression with regard to the angle: 2 × cos(2θ) × v²/g . Equate the expression to 0 and solve for θ : the angle which gives 0 is 2θ = π/2 ; hence θ = π/4 = 45° .