BDC retical calibration??

One last one to prove the BDC will work on any cartridge

Here's a 45/70 Gvt Hornady Subsonic (410gr Sub-X @ 1050 fps MV), zero'd @ 100 yards

wDzxnFA.jpeg


When scope is turned to highest mag :

first line down @ 110 yards
Second line down @ 130 yards
Third line down @ 147ish yards
Tip of post @ 167ish yards
 
The quick and dirty fix is pretty easy

Say your set-up calls for a 200 yard zero and you’re shooting at 500 with the appropriate stadia line. To your horror you’re hitting 1MOA low, or a smidge over 5”. Adjust your scope so the 500 yard aiming point hits at 500. You will now be 1 MOA high at 200, or 2 X 1.045” for 2.090”. Who cares? The error at 300 will be less than 1 MOA, .66 actually, which also happens to work to 2”. 400 is .33 MOA error or a whopping 1.37”. 500 is right, because you made it right.

Don’t let your errors magnify with distance. Make the correction out where it matters, and move the error back to where it doesn’t.

Of course this involves actually shooting🤣
 
if anyone has to use a bdc on a hunting rifle on big game up to 440yds they should not be in the field hunting
the trajectory of any standard cal out to 440 yds is easy science
on a varmint cal that's a different game
i'm talking small varmints gophers crows and even those are not difficult to hit out to 300 yds with a standard duplex crosshairs
 
snooker said:

KootenayNewb, If you haven't already, check out something called "Maximum point blank range".​

It's another way of using your scope zeros for hunting scenarios.
Just something to consider.
Click to expand...
Very cool concept, takes alot of the guessing out of determining the range of your target. Just gotta learn how to recognize your maximum distance and stay within it! Pretty much eliminates the need for BDC reticals.

To confirm I understand this chart correctly.

After sighting in a scope at 3.42" above the bullseye at 100y, all PERFECT shots fired at targets between 0-304y will hit an 8" target.

Targets at 0-21y POI will be below the center, between 24-247 POI will be above center, and from 258-304 POI will be below center again.

If the target was at 22 or 259 yards impact would be center of the crosshairs.

Targets beyond 305y either get to walk or POA raises a little bit.
 

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Yes, you've got the concept.
Just have to determine distance to your target---that's where range finders can be handy.
My club only has a 100 yd range max. And my hunting is pretty much 300 yds or less.
This concept keeps a person from shooting high, over your target.
There's a saying--"Shoot hair--not air"!
 
snooker said:
Yes, you've got the concept.
Just have to determine distance to your target---that's where range finders can be handy.
My club only has a 100 yd range max. And my hunting is pretty much 300 yds or less.
This concept keeps a person from shooting high, over your target.
There's a saying--"Shoot hair--not air"!
Click to expand...
The next skill is recognizing your 300y in the field without a range finder. The old timers didn't use them and did alright.
 
KootenayNewb said:
The next skill is recognizing your 300y in the field without a range finder. The old timers didn't use them and did alright.
Click to expand...
A regular old boring Duplex (Leupold copyright but widely copied) reticle spans 3 MOA from center to any of the tips of the thick posts or 6 MOA from post to post at max power. That’s 18” at 300 yards, so if the body depth of a deer sized animal fits between the top and bottom posts there’s your 300 yards. If the body is bigger than that spacing it’s under 300; but in either case its a green light to pull the trigger.

But wait; there’s more.🤣 The bottom post makes a perfectly adequate 3 MOA secondary aiming point, given just a bit of thought. It takes over when you get tired of seeing your crosshairs against the sky. If that seems like too big of a gap, don’t tell the Mil dot guys or they will get all butthurt. Speaking of Mils, the distance from the center to where the post gets to its full thickness actually is 1 Mil, so of course post to post on the thick point is two mils. Nobody gets left out.

A lot of thought went into that boring old reticle. There’s nothing new about it, but a lot of people have been walking around with all the rangefinder they needed and didn’t even know it.
 
Dogleg said:
A regular old boring Duplex (Leupold copyright but widely copied) reticle spans 3 MOA from center to any of the tips of the thick posts or 6 MOA from post to post at max power. That’s 18” at 300 yards, so if the body depth of a deer sized animal fits between the top and bottom posts there’s your 300 yards. If the body is bigger than that spacing it’s under 300; but in either case its a green light to pull the trigger.

But wait; there’s more.🤣 The bottom post makes a perfectly adequate 3 MOA secondary aiming point, given just a bit of thought. It takes over when you get tired of seeing your crosshairs against the sky. If that seems like too big of a gap, don’t tell the Mil dot guys or they will get all butthurt. Speaking of Mils, the distance from the center to where the post gets to its full thickness actually is 1 Mil, so of course post to post on the thick point is two mils. Nobody gets left out.

A lot of thought went into that boring old reticle. There’s nothing new about it, but a lot of people have been walking around with all the rangefinder they needed and didn’t even know it.
Click to expand...
This I'm going to reference again!
 
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