The Duplex Reticle On Your Scope

[Blaine]

You all prolly know this already, but......After you sight in your rifle in at 100 yards (or where ever) place the intersection of your bottom, heavy/light reticle on the bullseye, and shoot a group. It will be higher than your 100 yard POI....Using a table, or a SWAG you now know how to holdover on those longer shots when you have to hold over for a deadly POI.

[Old Savage]

7" for a Leupold 4x at 100 yds

[Blaine]

7" for a Leupold 4x at 100 yds

About 1 foot for my 2.5x Leupold Scout, 300 grain Winchester 45-70s I'm hunting with this year on the 1895GS....That translates into (close to) dead on at 200yds. with that load.

[handirifle]

My 30-06 will go 2" high at 100, allowing for a hold on the back line of a deer at 300 and the tip of the bold cross hair on target at 400.

[Malamute]

The point of the duplex is my aim point for the 600 yard plate with the Ruger 308 using ball ammo. Scope is an old Weaver 4x. Never checked it at other ranges, just figured out its the hold point for that range and load, sighted about 3" high @ 100.

[Dave]

One day I was shooting and started talking to a guy there on the line. He asked me if I knew how to use the duplex as a range finder. I told him no. I put out a 1" grid target at 100 yards and we looked to see how many inches were between the tips of the wide part of the duplex.

I can't remember how many inches were between, but once we saw that he did a ratio calculation based on a deer being 18" from the top of his back to the bottom of his belly. Then he said based on that calculation if a grown deer didn't fill up the space between the points of my duplex top to bottom it was more than 150 yards away.

He did it fast and I couldn't do it again but he was right. That info makes it easy to tell if a deer is close enough to hold dead on.

The way he did it was if there was 7" between my duplex then it would be 7" at 100 yards is to 18" at x yards or something along those lines.

7/100 = 18/x

[Stan in SC]

I was always of the opinion that the distance between the two bold points was 30" at 100 yards.


Stan in SC

[AJMD429]

I was always of the opinion that the distance between the two bold points was 30" at 100 yards.

I think it varies with the make of scope.

ALSO it varies with the magnification setting (unless you have a very fancy 'first-plane reticle' scope).

You can also take advantage of the 'duplex' joint to know where two different loads shoot from the same gun. At 4x the scope on my .300 Blackout is 100-yard zero'd for subsonic loads, and the supersonics will be at the top 'duplex' joint. I have to do some more range time (shucks ) and see where the two loads are farther down-range; it would be nice to know where the two loads cross down to the center and other joint.

[Blaine]

it would be nice to know where the two loads cross down to the center and other joint.

I would think that a ballistics program could tell you that....

[AJMD429]

I would think that a ballistics program could tell you that....

Yep. I just want to get it verified at a longer-range. Extrapolating back to 50 yards from 300 always works better than going from 50 yards to 300...

[Sixgun]

I was just doing that 2 weeks ago on my Colt 6940. Dead on at 200------- the 69 gr. Sierra Matchking nails the 300 meter pig at the beginning of the Leupold 2 X 7 duplex. I have no idea how that works out or how many inches it is. I just know it works. I guess you could call it a "poor mans mil-dot".

[Malamute]

I think the Leupold scope manuals have all that size info for duplexes. I have a Leupold VX-2 2-7 with what they call a long range reticle, and it has a couple dots between the cross hair and duplex point. It has info in the manual about what spacing that represents at different ranges and powers, and it has points on the power scale that represent range use and perhaps to make aim points consistant for certain ranges. It's been a while since I read the manual. The dots can be used as aim points for various ranges, and used as ranging indicators for sizing things. It looks real simple looking thru the cope, but theres a fair bit that can be done with it. They also have a Boone and Crocket reticle on the VX-3 scopes that is a nice ranging tool.

If you want the most ranging capability, you can measure the thickness of the duplex wire also, and it gives another indication when ranging