Duplex Reticle Calibration and Ranging
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- Опубліковано 15 вер 2024
- This video will demonstrate the method to calibrate and use your duplex scope reticle to figure the range to a target of known height. Many videos exist showing the use of Mil Dot reticles to establish the range to target, however, this video deals only with ranging using a duplex scope reticle.
This was good work .articulate , concise,and very easy to understand .thanks for a great video
I really like your Tags on the scope. This is a very useful video. Thanks.
Well done. Complex. Concise and useful.
Very nice explanation. Well done.
Please would you make a related video explaining how to use the duplex reticle to compensate for bullet drop once you know the range.
Thanks
Well done sir. I also love to apply subtensions for downrange zeroing and rangefinding. The only fun thing there is for applying the algebra we learned in school so many years ago. One example was when a buddy asked us once how big a certain target was at 1000 yds. we were shooting at. We used a mil reticle at the optics highest power (not the cald. magnification), and reverse mil'd it's subtension on a 500 yd. target we knew the size of, and simply filled in the unknowns with the new values. We bracketed the 1000-yd. target and calcd the target size then. When we measured it, it was .3" off at that range--couldn't believe it, but man was it fun.
Well, I was never much for variable scopes because every single time I took a shot at big game the scope was set on 4 x or 6 x. I like fixed power scopes. The choices are becoming rare today. I found out thru an experiment I did with some 130 hand loads in a Winchester XTR M-70 that I bought some 44 years ago that I mounted a fixed 4x M-8 Leupold scope on. I zero spot on at 200 yards. What I wanted to know was how far I could shoot using the junction of the thin and thick part of the duplex in that sight and the bullets, in this case, 130 gr Speer SP. would hit the center of the target. If I remember right, I don't have the notes from that handy, yeah I keep records of every shot I ever shot from a centerfire hunting rifle. It was around 380 yards or so because the bullets were hitting just 3 inches low on a 400-yard target as I recall. I didn't even have a chronograph then I could not afford one. and I was loading surplus 20 cannon powder from WW-II that Hogden called 4831, I bought 50 lbs of it in 1968 with lawnmower money, my mom was not happy but I fed 270's and7mm RM to the Early 1990s off of that 27 dollars. It does not matter much today when good laser range finders can be had. I know for a fact that I only shot one deer past 300 yards. That one was one of the quickest shots I ever made too- Big Mule Deer Buck in Montana. The outfitter I was with put the distance at very close to 400 and was surprised that he called the bullet placement wrong, I put the 130gr Speer SP right thru the heart, I was shooting a fixed 4x and an old Winchester xtr. Then again Jack O'Connor wrote about this stuff a long long time ago.
I gotta watch this a few times thank you sir.
Got to watch again. Just new to this
The best explanation, thanks
Thanks a lot sir your video was really helpful it made me really understand duplex
And this is why I bought a laser rangefinder.
A very real problem with laser rangefinders at long ranges, is the difficulty holding the laser beam on a target. Because of the magnification and small target, every little shake moves the laser beam off the target.
@@CletusLeonardLee The new ones with rapid sampling greatly reduce this problem.
I never used a range finder, but I plan on getting one, but I feel shooters should round themselves out by learning how to get it done with as little electronic devices as possible. I mean what happens when we lose our GPS and rangefinders and forgot to recharge or bring our batteries. And we have to borrow some body else's or go home all together.
I have a lazer rangefinder but still have my chart with the pre math to range with my reticle. Un less you have two rangefinders you only have one. One is none and two ways is one. Alway have a backup and know how to use it. Ps. In ware a rangefinder will give your position away.
Excellent video! Will help me establish the subtensions of the Dispatch 600 reticle, for which I can't find any info. Thank you!
Thanks
great video :) you cant even imagine how many long rage deer this video got me
Well said. I'm in the class. Thanks teach.
Made my day tanks very much
What if ground hog isn’t standing. Wouldn’t your measurement be off trying to measure it not standing? Or if shooting an armadillo. Most times, it isn’t standing up so the distance will be off if measuring either animal standing or not standing. Trying to understand.
Damn fine explanation!
Pure Gold.
Thank you. Appreciate the info. Happy hunting.
Great vid...Thanks
Possibly a dumb question, So do you range your target at the lowest setting ? Using magnification your target changes size so if you dial it up you could easily mess up your range calculation no ?
It will help me on my next hunting trip
So I am guessing that the 2.75 of an inch is just an example at 100 yards and my scope will probably show the subtension to be smaller or greater then 2.75, because the Duplex Reticle drawn in ink is not actually what Mcgiiver L discovered to be so, on the scope he showed. The tags are to small to read, but rather it is just an example on how to calibrate your own Duplex Reticle scope. I was hoping to just use his calibration with my vintage world class 6-24x50 unfortunately not from Japan. Lazy. Guess I better get 100 yards of string.
.
You are correct in that the 2.75" I mentioned is just an example. Your actual subtension value is probably different. There are two tags on my scope, one is the formula to calculate range, exactly like the example I had pinned to the wall. The other tag is the load, which shows what bullet and powder charge I have standardized on. This little tag coordinates with the load shown on the trajectory sticker on the buttstock.
I felt like basic training all over again when that kid in the back just screams out when are we going to shoot and gets hit with An endless amounts of little man in the woods
Nice video buddy
Thank you for your video greatly appreciated it helping me out greatly. You mention the adjustable objective on front of scope, can you tell me how that was suppose to be intended to be used? I know you said that it is not accurate, but I still would like to know seeing bushnell mention nothing about it in specs? Nor can I get any information about my model elite 3200
The adjustable objective on a scope is intended to be adjusted to remove parallax error. The numbers on the scale, are really unnecessary. They are only a very rough guide to range.
my head hurts
x100000000
Oh MY !
Is there anything for meters?
I do not understand what the 2" stands for between the M.O.A scale and the Mil scale, on the bright pink board represent? Other then that very helpful video.
It doesn't stand for anything in particular, other than simply the distance from the line below the "2"", to the line above.
helpful, thanks.
Very well done….still something I’m going to have to think about because I cut most of my math classes…..lol
Do the math before hand. You know what you will be shooting at. No time to do math on the fly. Just read it of your range/hold over table.
I make use of a MRAD scope and did all the math before hand. I save time and are on the dot with ranging and DOPE
This is very helpful, but does the formula work the same way in metric?
Do you plug in 100 at the top of the equation to represent the 100 yards at which you calibrated?
In other words, if calibrating at 50 yards would I plug 50 in at the top of the equation?
try 100 or 50 metres not yrds.
It should if you use metric values. The math is the same just the different form of measurement.
Complex and PITA and slow. Now I understand why there's FFP and mil 1/10 based reticles. I still use a duplex on my 270win but use an modified version of the stupid MPBR method. I have an established zero, then an hold for at 300yd, 400yd hold, and the 500yd hold correlates with the thick point of the bottom reticle post. It works very well to 500yds with an rangefinder and is fast. If I need to range using a reticle I b prefer an FFP style reticle but my 270win is fine at 400 and perhaps 500yd. After that your really running out of velocity and energy.
Do you have the special target size ?
I am not sure what you mean "special target size". The pink target can be any size. You just need to make the marks on it very visible when viewed from 100 yards. The pink paper is 14" x 22", hope that helps.
It takes the fun out of shooting...
and how is this easier than MOA? .... im so damn confused.... you need to be a wizard to figure all this out ... i just want to hit my target and you want me to do calculus and magic to figure out how to use a duplex reticle ... it should be called a complex reticle
Real men hunt with duplex reticles
Now thats some funny stuff!!
I just use the "Force" like Luke Skywalker. He wasn't good at math.
No way to mil or sub tend at no 1234 yds.. no way no how....
U be way way off ,,even a few yards , and miss if you imply a shot at that distance....
But ,it will tell you to git a lot dang closer ......
I am not sure I understand your comment. You most certainly could subtend to estimate 1234 yards, it just must be done carefully. It should be obvious, that the numbers in the video were just chosen to illustrate the method, not advocate shooting game at that distance.
yeah your number is wrong its 474 yards not 1234. you screwed up on the subtension measurement half of 2.75 is 1.375
@@dadlife1451 During reticle calibration, in this example, we determined that the subtension value, point to centerline, is 2.75". When we lay our reticle on the deer picture, belly to back of 17" , is covered by 1/2 of a subtension or 0.5. So we use 0.5 as N in our formula Range = 36.3(h)/N = 36.3(17)/0.5 which equals 1234 yards. The 2.75 subtension value is already taken into account in the constant 36.3.
Holy cow, just get a rangefinder and a scope that subtends in moa. But then you have to understand moa, HEAD explosion! BOOM!!
Who the hell walks around with a calculator while hunting?
These days? I would assume literally everyone, seeing as everyone has a mobile phone these days and all of them are equipped with a calculator app. There are probably a lot easier techniques and alternatives though, and if you would be using your phone for making those calculations you might as well use a ballistic calculator app instead. There are several very good ones available free of charge.
Actually, I do. When groundhog hunting, I have a solar credit card sized calculator and a drop table taped to the off side of my buttstock.