Disagreement about bullet drop

[TriumphantApe]

So lets say a 300 meter "horizontal" shot has 20 inch drop at target, my thinking is that up on a ridge shooting the same target at 300 meters with a 45 degree downward angle the drop would be less.

All conditions being equal for both shots, does gravity have a reduced effect on bullet drop in downward angles?

[Toomer]

drop is a function of flight time. the total drop rate of any object is the same (barring terminal velocity).

300 meters from target is not necessarily the same as 300 meters of flight distance. a raised target may be 300 meters away (measured on the ground); however the bullet may have to travel 400 meters. in this case, bullet drop would be better calculated off of the 400meter number.

[TriumphantApe]

drop is a function of flight time. the total drop rate of any object is the same (barring terminal velocity).

300 meters from target is not necessarily the same as 300 meters of flight distance. a raised target may be 300 meters away (measured on the ground); however the bullet may have to travel 400 meters. in this case, bullet drop would be better calculated off of the 400meter number.

I think you're saying that the angle increased flight time, is this correct?

This is why I added all things being equal, so that the only difference is angle (in relation to Earth) is drop the same?

I tried to figure this out by doing a search, as it happens none of the calculators I came across had the angle difference.

[TexasJackKin]

It's a right triangle problem, with a range finder, you’re measuring the hypotenuse, but the bullet drops along side B, of the triangle. Bullet drop is a function of time but most bullets start with a small upward velocity, that has to be dissipated, before it's pure gravity. That's why mid flight the bullet is above the point of aim.

[Spyder]

...but most bullets start with a small upward velocity, that has to be dissipated, before it's pure gravity. That's why mid flight the bullet is above the point of aim.

No.

[2Stroke]

I think OP is talking about trajectory vs. sight picture. The steeper the angle the higher the point of impact, everything else being equal. Has to do with the direction of gravity relative to direction of aim.

[TriumphantApe]

It's still a mind bender for me but I found the "rifleman's rule" that explains it fairly well.

https://en.wikipedia.org/wiki/Rifleman%27s_rule

Drop is different for a bullet shot upward or downward angle.

[TriumphantApe]

Can of worms guys? It's a simple question (from my perspective anyways).
If you shoot at a target that is downhill from you (rifle at downward 45 degrees), is bullet drop less than it would be for the same distance but a horizontal shot.

[TexasJackKin]

No.

Why do you say no? To hit a target at long range, the barrel has to be pointed above the target, compared to the sights. The bullet has to rise, not because some magic is happening, but because it was launched on an upward trajectory.
That is the small upward velocity that I'm talking about.

[Jimmy's]

More or less.

[TexasJackKin]

Can of worms guys? It's a simple question (from my perspective anyways).
If you shoot at a target that is downhill from you (rifle at downward 45 degrees), is bullet drop less than it would be for the same distance but a horizontal shot.

It's not quite as simple as you may think, but the rule of thumb is, shooting up hill or down hill, the bullet will hit higher than shooting horizontal.

[Spyder]

Why do you say no? To hit a target at long range, the barrel has to be pointed above the target, compared to the sights. The bullet has to rise, not because some magic is happening, but because it was launched on an upward trajectory.
That is the small upward velocity that I'm talking about.

Bullets don't travel upward when they leave the barrel unless the barrel is pointed upward.

"most bullets start with a small upward velocity, that has to be dissipated, before it's pure gravity"

Physics and stuff.

[sofbak]

^^^half the time....

Shooting uphlll, bullet will strike higher than it would with a horizontal POI and the same direct distance to target. Because (in rectilinear terms) a portion of the bullet's velocity is 180 degrees opposed to gravitational acceleration. Thus bullet does not fall as quickly as it would in horizontal flight.

Shooting downhill, the opposite is true. A portion of bullet velocity is acting in the same direction as gravity, thus bullet falls faster than it would in horizontal flight.

If you're not familiar with rectilinear algebra, the above may not be clearly understood, but fizzix is fizzix.

[StuckInTheP.R.O.Ca]

Can of worms guys? It's a simple question (from my perspective anyways).
If you shoot at a target that is downhill from you (rifle at downward 45 degrees), is bullet drop less than it would be for the same distance but a horizontal shot.

To put it simply. If you shoot at a horizontal target at say 400 yds and scored a bullseye, then shoot again at a target at 400 yds but at a 45 degree angle your shot will impact high compared to the horizontal level shot. Also it doesn't matter if the shot is up or down. It will still impact high compared to a level shot.

[russ69]

...Bullet drop is a function of time but most bullets start with a small upward velocity, that has to be dissipated, before it's pure gravity...

All objects fall at the same rate regardless of velocity or angle. That rate is the acceleration of gravity or 32 fps^2 IIRC. The only factor that changes is the time of flight to target.