Jim Watson
New member
Or even aperture sights. I have not seen an open sight on an AR except where somebody attaches pistol sights as backup when their scope fogs or their battery goes flat.
Bullet drop from 100 to 200 yds
- Thread starter NHSHOOTER
- Start date
Well, the acceleration of gravity is constant, it doesn't care how big or small the bullet is. Generally speaking the faster the bullet, the shorter the flight time and the less drop over a given distance, but there is another factor that can give the perception of less drop with the same bullet, sight height.
Also remember bullet trajectory is a curve, and not linear, and the relation in any 2 ranges is not the same. I know it sounds wrong, but run the numbers for yourself.
Example, I saw jmr40's post above "6.5 Creed/143gr, 2650 fps -4"@200" and initially thought he was out of his mind, because that is not that far off my 6.5-06 load, only ~175 FPS slower, and mine only drops ~1.5" between 100 and 200. Except that it doesn't.....
I went back and looked, and with a 200 yard zero, it hits ~1.5" high at 100 yards. But, and this is a huge but, if I zero it at 100, my drop to 200 is ~3.0".
How can it have twice the drop? Easy, it doesn't. Both of those numbers are the same, both are 1.5 MOA.
OP, you should rerun your numbers, because to really only have ~1.5" of drop to 200 from a 100 yard zero, a 55gr FMJ would have to be going about 3700 FPS.
The know-it-all at the range gave a decent rule of thumb, if you have no other information available, then zeroing at 50 should get you in the ball park with most rifles.
However, these days when most folks have internet on their phones (or a ballistics app), there is no reason to limit yourself to rules of thumb. Measure your sight height and velocity (if you are able), and run the numbers for 200 yards and see where it would hit at the shorter ranges. I suspect for .223 it will be about 1.5" high at 100 yds.
Also remember bullet trajectory is a curve, and not linear, and the relation in any 2 ranges is not the same. I know it sounds wrong, but run the numbers for yourself.
Example, I saw jmr40's post above "6.5 Creed/143gr, 2650 fps -4"@200" and initially thought he was out of his mind, because that is not that far off my 6.5-06 load, only ~175 FPS slower, and mine only drops ~1.5" between 100 and 200. Except that it doesn't.....
I went back and looked, and with a 200 yard zero, it hits ~1.5" high at 100 yards. But, and this is a huge but, if I zero it at 100, my drop to 200 is ~3.0".
How can it have twice the drop? Easy, it doesn't. Both of those numbers are the same, both are 1.5 MOA.
OP, you should rerun your numbers, because to really only have ~1.5" of drop to 200 from a 100 yard zero, a 55gr FMJ would have to be going about 3700 FPS.
The know-it-all at the range gave a decent rule of thumb, if you have no other information available, then zeroing at 50 should get you in the ball park with most rifles.
However, these days when most folks have internet on their phones (or a ballistics app), there is no reason to limit yourself to rules of thumb. Measure your sight height and velocity (if you are able), and run the numbers for 200 yards and see where it would hit at the shorter ranges. I suspect for .223 it will be about 1.5" high at 100 yds.
"...I don't see him all that often..." That's probably good. He's very confused.
Where you sight in at 100 to be on target at 200 depends a lot on the barrel length, bullet weight and muzzle velocity.
However, a factory 55 grain FMJ gets sighted in 1.4" high at 100(your 1.5" is close enough for a 7" steel target at 200.) and it'll drop 7.1" out at 300.
Gunner's Den is ok except they usually have a sight in distance that's kind of unrealistic. I think they may be using a ballistics program.
"...just like the guy at the range said..." Except for the part he thinks ALL cartridges do that.
Where you sight in at 100 to be on target at 200 depends a lot on the barrel length, bullet weight and muzzle velocity.
However, a factory 55 grain FMJ gets sighted in 1.4" high at 100(your 1.5" is close enough for a 7" steel target at 200.) and it'll drop 7.1" out at 300.
Gunner's Den is ok except they usually have a sight in distance that's kind of unrealistic. I think they may be using a ballistics program.
"...just like the guy at the range said..." Except for the part he thinks ALL cartridges do that.
Don Fischer
New member
To most people the term drop means how far line below line of sight a bullet will drop. The rise is above line of sight.
ShootistPRS
New member
The difference in bullet drop between 100 and 200 yards depends completely on the velocity of the bullet. As someone already pointed out, the acceleration of gravity (here on earth) is a constant. Only the time that gravity is pulling on the bullet determines its drop. Slower bullets take longer to get to their targets and have a greater velocity in the downward direction than faster bullets.
A 38 special bullet drops further from 100 yards to 200 yards than a 30-06 bullet because the 38 bullet takes longer to get there. The two bullets have the same drop over the same time periods but the faster bullet goes farther in that time.
A 38 special bullet drops further from 100 yards to 200 yards than a 30-06 bullet because the 38 bullet takes longer to get there. The two bullets have the same drop over the same time periods but the faster bullet goes farther in that time.
Easy, come up ~3".
Just curious, how old is this person?
As generalizations go, "most centerfire rifles have about 3" of drop between 100 and 200 yards" is not a bad one.
Looking at the chart on the link you provided, damn near all of the more common calibers fall between 2.5 and 3.5 inches of drop between 100 and 200 yards. It is less true once you get above .30 caliber, because the bullets get heavier and tend to be slower. Sure, there are exceptions, 220 Swift, and some of the magnums have less, .30-30 and a few others have more.
So for most rifles he is right, coming up 3", or 1.5 MOA from your 100 yard zero will put you within 1/2 MOA for elevation at 200. On the target you describe, taller than it is wide, that will be fine.
The "Just zero it at 50 it will be on at 200" I am much more skeptical of.
Just because we're old, it doesn't mean we're stupid. I'm 69 and know the trajectory of my various calibers (9 rifle) I handload for and how they'll preform in a given rifle. While sighting in at 100 yds was the given when I started shooting 60 yrs ago, I realized 15 yrs ago that when I sight in my rifle at 200 yds, I've got a much more useful operating range where my bullet path is within ± 2" of the sightline.
TJB101 - Time to get a new ballistic calculator. Zeroed at 100 yds with a sight height above the bore centerline of .9" (typical irons height of a bolt gun), you're 2.88" low at 200 yds using your velocities and a 55grn spitzer pointed boat tail bullet. With a sight height of 2.6" (height of an AR sights) and again, sighted in at 100 yds, you're 1.88" low at 200 yds.
math teacher
New member
"Drop" as stated in the ballistics tables is measured from the line of the bore. "Path" as stated earlier is a curve measured from the line of sight. Look at the drop column in the ballistics tables and you will see that all bullets drop like crazy after 300 yards, regardless of the cartridge, due to the acceleration of gravity.
Nothing wrong with his calculator, look at it again. He is not zeroed at 100 yards, it is at 50, addressing where the guy at the range said to zero.
He is wrong though when he says "Tad over 1/2 in drop @ 200 yards". That column is not in inches, it is in MOA, so instead of .6" low it is .6 MOA low, or 1.2 inches at 200 yards.
Not perfect, but if you did that you should be able to hit a 7" tall target at 200 yards.
Art Eatman
Staff in Memoriam
For most "deer cartridges" and the vast majority of all shots at Bambi, if you zero for 2" high at 100 yards, you can quit thinking.
"Just point it and pull. The freezer ain't half-full."
"Just point it and pull. The freezer ain't half-full."
math teacher
New member
Amen Art. I have been preaching for years that if you just sight in about 2 1/2 inches high at 100 yards, you will maximize the point blank range for deer with just about any rifle. I won't quibble about a half inch.
Actually, there is. Look at the muzzle and 50 yd readings. Both are zero so either his sights are lined up with the bore axis and the muzzle reading is right while all of the rest are wrong, or the muzzle reading is wrong.
Either way, if the OP copied the printout of a ballistic calculator that gave those readings, then that calculator is dead wrong . . . inches or MOA, it don't matter cause the bullet starts dropping and slowing down the instant it leaves the barrel, not 50 yds down range.
Drop is determined by flight time and the acceleration of gravity. That is it, nothing else enters in to it.
Flight time is determined by velocity, both initial (muzzle) velocity, and retained velocity at the target (which varies by ballistic coefficient).
Again, while not perfect, if someone showed up at the range and wanted to make hits at 200 yards, with unknown muzzle velocity and BC, and you didn't have access to a ballistic calculator, assuming ~3", or 1.5 MOA, of drop to 200 yards is a pretty good rule of thumb.
ShootistPRS
New member
If you don't know muzzle velocity or ballistic coefficient a ballistics calculator would be worthless any way. If you are at the range and want to hit at 200 yards then sight it in at 200 yards. With my 30-06 I hit just under 1" high at 100 yards and right at 1 inch low at 200 yards. My point blank range is calculated on no more than 1 inch above or below point of aim.
The '06 is dead on at 174 yards.
The '06 is dead on at 174 yards.