Frame of reference matters, so to clarify, the angle between the bullet trajectory and the earth upon exiting the muzzle does not increase, and starts to decrease the moment the bullet leaves the gun. .
I never stated that the angle between bullet trajectory and the earth upon exiting the muzzle increased, and agree that in almost every case it starts to decrease the moment the bullet leaves the gun.
As you said, frame of reference matters - Your average Joe describing ballistics isn't visualizing a line of bore - they're using the only reference they have, line of sight.
The projectile does not counteract the force of gravity, and begins falling the instant it is no longer being supported by the barrel.
A projectile launched at a horizontal target with an upward trajectory from the line of bore relative to the line of sight absolutely does NOT begin falling the instant it leaves the bore. It begins falling the instant it leaves barrel relative to the line of bore (again frame of reference). But relative to the only things that you can actually see when squeeze the trigger - the line of sight and terra firma, the bullet does indeed rise for a brief period of time.
Being subject to the force of gravity does not equal falling. I am subject to the force of gravity right now - I'm not falling. When I get in my plane next week for my scheduled trip, I will be subject to the force of gravity, but I will in fact rise as I begin that journey (for a significant period of time I hope!) Because the bullet is no longer accelerating when it leaves the muzzle, the upward force counteracting gravity is quickly overwhelmed, and the force of gravity accelerates it's return to earth. But the energy of the bullet imparted to an upward trajectory does in fact counteract the force of gravity for a brief period of time.
Pretend I've got a target paper (no backstop) placed at 1000 yards exactly 4 feet off the ground. I fire a rifle perfectly sighted in to be dead on at 1000 yards from that rifle that has the end of the muzzle precisely 4 feet off the ground while simultaneously dropping a bullet from exactly 4' in elevation immediately next to the muzzle - which bullet hits the ground first?
Please don't tell me that you believe they will hit at the exact same time, because they won't. The bullet dropped from the hand will hit significantly sooner than the bullet fired at the 1000 yard target. The difference in impact times can only be because a force (a portion of the bullet's initial velocity) was utilized to counteract the force of gravity (briefly).
If it helps you or anyone else purely to describe ballistics from the reference point of line of bore, I have no issue with it. To jump up and down and tell someone that bullets don't rise when people stating such are clearly referencing light of sight is silly and disingenuous.
David
