What does this ballistic chart mean?

Lets try a slightly different approach.
This is a chart of the 2 sets of numbers, each is color coded to its data.
I read the 2 sets as
"This is the actual drop from your 200 yard zero" but at a distance of 100yds.
These are the MAGENTA numbers & tracks.

"This is the amount below the line of sight you bullet will be at theses distances with a 200 yd zero"
These are the Blue colored numbers & tracks

(Note although it says "100 yd" the actual "0.00" is at the 200 yd range in both tables.)

(Images (C) Wogpotter 2015)
drops_zpsjxcxg3g2.jpg


Why have both sets?
Easy!
For different methods of aiming off for distances other than the zeroed 200yds where the path is 0.00" in both cases.

If you're gong to adjust your Point of aim by clicking the scope knobs this is how much you change it (with a 1/4" click for 100 yds you multiply by 4@ 100 2 @ 200 & so on.)
That's the BLUE numbers.

If instead of twiddling you aim off by the opposite amount then you use the Magenta ones.
Rephrased as:
"To hit dead on with your 200 yd zero aim 39" high at a distance of 500 yds.
 
1st column: range in yards.
2nd column: MOA equivalent of 3rd column.
3rd column: poi relative to poa.

They may be named differently, but that is what they really are.

BTW, the sight is 1.6" above bore axis in this gun.

-TL
 
Ballistics chart

In reference to post #18
This is an example of the chart Remington, REM Shoot puts out!
I am thinking the 'path' column is the one I need to use.
 

Attachments

  • 444Marlin.JPG
    444Marlin.JPG
    61 KB · Views: 8
Thanks emcon5, I'll set the first drop column to "inches" and the second column to "MOA or MIL" depending on which scope I use.

Stag - good read on that link, thanks.
 
Yep, Path is what you want. Drop is pretty much useless.
Click to expand...
I'm not a math guy--but I believe theoretically you should be able to calculate muzzle velocity and consequently a ballistics table if drop at a known target distance is known--definitely useful if you have unknown ammo and no chrono--no?
 
I'm not a math guy--but I believe theoretically you should be able to calculate muzzle velocity and consequently a ballistics table if drop at a known target distance is known--definitely useful if you have unknown ammo and no chrono--no?
Click to expand...

Sure, if you can make your rifle perfectly level, at a known distance above sea level, then have the target at the exact same distance above sea level.

Or, you could zero the rifle at 100 yards, then shoot at a farther distance and see how much the actual drop is. You can then tweak the velocity in the ballistic table until the prediction matches the measured results.
 
I'm not a math guy--but I believe theoretically you should be able to calculate muzzle velocity and consequently a ballistics table if drop at a known target distance is known--definitely useful if you have unknown ammo and no chrono--no?
Click to expand...

If you assumed a vacuum, yes. The assumption there is that the bullet speed is a constant and equals muzzle velocity*. The reason you could do the math in this case is because you know exactly how long it takes the bullet to drop the known distance, so you can calculate flight time to target. Because of no air resistance and the assumption of constant bullet speed, you can calculate the velocity, and therefore the trajectory. I believe calculus would be needed to do this simple (and useless) model.

I have to think it would be way more useful, and far more fun, to just go to the range and see where the bullet hits when you pull the trigger. I know that for me, it doesn't mean a hoot if the ballistics table says there's a 10" drop at 200 yards when zeroed at 100, if my group at 100 is already 4". I can't predict squat at 200, except the group size surely won't be smaller than 8". :)

*Muzzle 'velocity' is kind of an unfortunate term, because what we really mean when we use it is bullet speed at the muzzle. 'Velocity' specifically means the combination of speed (feet per second, for example) and direction. It's an important distinction when talking calculations, models and math...not too important when talking about shooting and hitting something.

Where the distinction IS important is when it's important to know that some force has to be applied to anything to change its velocity...even if its speed doesn't change. An example that's easy is a kid sitting on a merry-go-round, being spun at constant rpm by his associates. His speed isn't changing...but his velocity definitely is. That change in velocity is why he has to 'hang on'...it takes force to change velocity, and one way to change velocity to change the direction of motion--regardless of any change in the speed of that motion.
 
Last edited:
I have to think it would be way more useful, and far more fun, to just go to the range and see where the bullet hits when you pull the trigger. I know that for me, it doesn't mean a hoot if the ballistics table says there's a 10" drop at 200 yards when zeroed at 100, if my group at 100 is already 4". I can't predict squat at 200, except the group size surely won't be smaller than 8".
Click to expand...


That's funny bongo - makes sense to me!
 
You must log in or register to reply here.
Back
Top