Duplex Scope for Rangefinding

[Cowboy]

I am curious if anybody here has experimented with using the span of the fine cross hairs to judge distance.

I played a little last weekend with my scope, and have come up with if the scope is set on 9X the fine wires measure 6.25 inches long at 100 yards and 25 inches long at 400 yards.

What this tells me is an elk with a chest that is smaller than the fine wire length is over 400 yards. I can also use fine wire length to judge bullet drop. Half the fine wire length is about the holdover at 400 yards for my load.

So far everything is checking out. Anybody have any notes to compare with this?

 

[RELH]

Cowboy;

I have been using this system for over 20 years with my 25-06 deer-antelope rifle. I have a Nikon Monarch 3X9 scope. If I put the center of the cross hairs,at 9 power, on the top of the back of a muley deer, and his brisket hits the Vertical wire where the thick part turns to fine wire, he is 400 yards away. If his chest is smaller, he is over 400 yards. If his chest is larger then the above span, he is under 400 and I use the cross hair as my aiming point since I sight in at 3" high at 100 yards.
I have found that if the animal is at 400 yards, the top of the thick vertical wire,where it meets the fine wire, is dead on for a 400 yard shot.
Just remember to use this at the 9 power setting, because if you leave your scope at a lower setting, you will end up misjudging the range and shoot over the deer.
If a guy is willing to practice enought, most scopes can be used for judging the distance out to the range of 600 yards.
My Father-in-law used to have the Lee Co. put a 3 minute dot in the center of his Leopold scopes and he used that dot as a range finder out to 600 yards or more. I once saw him put two shots into a deer's chest that was measured at a distance of 6/10's of a mile, and both shots were within 4 inches of each other. Several of his rams and sheep were dropped at a distance of 400-600 yards and all were one shot kills. Being a farmer, he was shooting his Weatherbys year round at his ranch range that went out to 600 yards.

RELH

 

[rost495]

All scopes subtensions may be different. And they may vary as you change power. That being said learn what yours covers and use it. No questions that it works. On animals it can vary by the size of the animal vs the next one BUT is usually much closer than guessing. And for holdovers or wind drifts it is much better than guessing.

The scope I'm working with currently has 8MOA subtension all the way across. I'm zero'd on the top duplex at 100, center at 200 and bottom duplex on the spine at 300 works well. (its muzzleloader hence the bad drops).

Keep it up.

PS glad to see someone else here realizes that you can make long shots if needed ethically. I get called down for it all the time. Yet I doubt that those folks fire from 4000-8000 rounds a year on average out to 1000 yards and have their own range out the back door to 600. It takes practice but is very workable.

Jeff