Zero range

Discussion in 'The Basics, Starting Out' started by Diverguy23, Oct 26, 2017.

  1. OptiCo.us

    OptiCo.us New Member

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    We're talking about different things. I meant sometimes people think that a longer zero range will increase the adjustable range of the optic. If they zero at 100 and run out of adjustment at 800 yds, maybe if they change their zero to 200 or 300yds they'll have more adjustment to reach out to 900 yds and further.....NOT.

    What you described is the range for each hold-off reticle subtension being influenced by the original zero range. You are correct.

    I might have misunderstood you but people can calibrate their duplex reticles by measuring the inches to the top of the bottom bar on a grid at 100yds, or just holdover with the top of the bar and measure how high your POI is at 100yds. For 2nd Focal Plane, suggest maximum zoom (corresponding to longer shots.)
     
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  2. johnnyk

    johnnyk Well-Known Member

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    I sight all my rifles for 300 yd zeros. I have done this all my life and it works for me. When building a profile for my rifle/bullet in my ballistic app, I list the zero as 300yds and look at the POI's at 100, 200 and 300yds. Example; my 270 Allen Magnum is 2.0" @ 100, 2.7" @ 200 and 0.0 @ 300yds, while my 6.5-284 is 3.2" @ 100, 4.1" @ 200 and 0.4" @ 300.
    I routinely review this info before/during hunts to re-familiarize myself with the rifle I'm using in the event a close shot presents itself and just dial from 400yds and out.
    Hope this doesn't confuse anyone. JohnnyK.
     
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  3. Bob Wright

    Bob Wright Active Member

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    Texting can cause misunderstandings for sure. My intent is to make sure all of us read the scope instructions and see if there is a better/accurate way to do it. I just stumbled on it during some slack time reading, as I have never used the stadia as intended. I have a calibrated turret in yards too, for 1000 yards. Now is my chance to test this method. 6 shots to zero and calibrate. 3 shots to test 300-500 yards. Zoom must be set as calibrated or I will have bad results using holdover stadia in this reticle. Will report back.
     
  4. 6MM06AI

    6MM06AI Member

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    This has been a great thread. I really enjoy reading all the different view points, while interesting, it still won't change my idea of 2" high at 100. And I don't expect my views to change anybody else and their way of Sighting. The main thing is to verify where that bullet hits at what distance by shooting and not solely relying on a ballistics app.
    While the magnums are pretty flat they pale in comparison to wildcat rounds, 20-250, 22-243, 606Ai. All three of those are 18 to 20" low at 500 and dead on at 300 with a 2" high zero. None of my magnums 300 win, 300 rum, 6.5 wsm can do that. They don't have to, they are made for bigger critters that don't bark and howl. But once again I love this thread, keep the ideas coming and thanks for all the input.
     
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  5. Greyfox

    Greyfox Well-Known Member

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    I’m not sure it makes a whole lot of difference, but I prefer my scopes zeroed for 200 yards for hunting and competition, but understanding the 100 yard dope should that range be my only option for a field check. I have not found that atmospheric conditions make a material difference in POI between 100 and 200 yard zero’s. I shoot elevations from 300’-4500’/ temps from 10F-85F; adjustments made with a Ballistic RF. Wind generally has to be accounted for at either zero range. The load for my primary hunting rifle has been standardized with same lot components, good for 1000 rounds and proven to be temperature stabile. Zero has maintained within a couple of clicks for several seasons. I’m not sure whether it’s due to parralax sensitivity at close range, bullet stabilization, or just plain psychological(me), but my 200 yard zero tests are generally more consistent, with better precision, then when using 100 yard zeros. Most importantly, I’ve been “nuts on” out to 1000+ yards.
     
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  6. Bob Wright

    Bob Wright Active Member

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    All good input! Do what works for you. Here is the update to the ballistic drop. My 7mm mag dropped 33 inches at 500 yards. When I adjusted the zoom knob to put the 500 yard mark directly in the group I shot, you can see in the photo, it is off the large delta just a bit at the new painted mark. So this is my new zoom range when going past 200 to 500 and not touching the turret.
     

    Attached Files:

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  7. Legionnaire

    Legionnaire Active Member

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    Nice solution, Bob. Thanks for the tip!
     
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  8. Barrelnut

    Barrelnut Well-Known Member

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    I do similar to calibrate actual drops the load produces with a Zeiss RZ-800 reticle. Works great.
     
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  9. red6x6

    red6x6 New Member

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    Really enjoyed reading the thread. Though I have hunted for many years I am an absolute novice in the Long Range Field. I recently bought a Swaro 4-12 x 50 with a BT for my 7mm Rem Mag. I originally sighted in to be spot on at 100yd and then used the ballistic calculator online to set the coloured buttons to indicate 200, 300 400 etc. In doing this I ran out of adjustment (42 clicks) at 575yd. I then decided to sight in to be spot on at 250yd so the adjustment in the BT would get me out to 650yd before I ran out of adjustment. This allows me to hunt deer around home and not have to touch the rangefinder or turret until I am looking around the 325yd+ distance. When chasing Tahr I have a set up that will allow me to shoot out to 650yds if conditions allow. Am I on the right track or am I missing something?
    This is set for 150gn BST factory load but I have just loaded up some 162gn ELD x for development so it will all change. Can I however approach sighting in the same way?
     
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  10. Bob Wright

    Bob Wright Active Member

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    I bought a 20 moa picatinny rail for my scope base. I checked the bore sight and found it would bottom out my vertical adjustment at 100 yards and not get me to zero. So, I played with shim stock up front to get my turret about 1 full turn up from bottom. My scope has 90+ minutes of travel, 30mm Leupold.
    Once I figured that .015 inch shim stock was good, I had 78 minutes left to play with going up. I then glass bedded the front shim stock and rear of the rail, and lightly set the torque of the screws to just "hold it" during cure, using release agent on screws and receiver, so that it can be removed in the future. By bedding it, it adds no stress to the receiver when torqued. Now I start at one turn up and have a great deal of vertical to use.
    Since I have no zero stop, I can visually tell when I go up to 1000 yards and return to my zero reference easily.
    That's one way....
     
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  11. red6x6

    red6x6 New Member

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    Thanks Bob. Good trick. The Swaro is only inch tube so I don't expect to have as much to play with. The rail may be worth looking at. Thanks again.
     
  12. Wallythe7mmWeatherby

    Wallythe7mmWeatherby Member

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    I'm a newbie, but the only reason I know of to have a zero not at 100 yards is if you wish to make what I call a "hunting" zero where you set your gun up so that you hit up to say 3" high at the peak of the bullet and then you know what range you'll end up hitting 3" low. Anything out to that range then you just put the crosshairs on and pull the trigger knowing you'll hit inside the kill zone even if it's not absolutely perfect

    If shooting targets or dialing in each shot, just leave the zero at 100 yards. No benefit to being at 200, although reading through there are some scope methods I'm not familiar with
     
  13. red6x6

    red6x6 New Member

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    Wally. If I sight in at 100 I run out of adjustment on the BT at about 570yds. By sighting in at 250 or so I can get out to 630yds before I run out. I get what you are talking about re hunting zero which is what I have done for years until I got a BT set up.
     
  14. Greyfox

    Greyfox Well-Known Member

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    As this thread keeps popping up on my e-mail since I gave a prior response, it forced me to think s a bit more about the reasons why ai have used a 200 yard zero for about the last ten years......when I extended my hunting range to 1000 yards(or so). Again, I wouldn’t die on any hill over using a 100 or 200 yard zero, but these are my perceptions..

    -In reality, where the zero is set doesn’t prohibit you from testing your zero at any range you choose if you have confirmed dopes. Setting the zero at 200 can make a 5-10% difference in turret or reticle traveled-riding on your particular set-up. With my primary hunters, I am able to stay within one turret revolution for over 90% of my hunting shots for the last several years. Not a big deal, but an attractive benefit, particularly in the heat of the moment. Fortuitously, with my primary hunter, a 200 yard zero in my average conditions, my from 200-1000 yards are easier values to commit to memory, and make adjustments(MOA) for distance or condition changes....mentally. 200yd=0, 300yd=2.0, 400=4.0, 500=6.5, 600=9.0, 700=12.0, 800=15.0, 900=18.0, 1000=21.5. These are easier values to deal with compared to my 100 yard fractional values. I actually tune my loads to confirm these values at my standard conditions.

    -At 200 yards, I find myself checking my rifle zero “and” my zero. I always check my zero from stable hunting or competition positions. Since switching to a 200 yard zero I’m surprised at how many of my .5MOA rifles became .25MOA rifles, a result of 200 yard conditioning, and frequency. A 200 yard zero forces me to concentrate much harder on the shot, consider wind(which can also effect a 100 yard zero), and make sure all form and settings are exact. While it may not be material for a lot of hunting shots, my standard of performance from myself and my rifle has increased. This can make a difference for the longer shots.

    -Even with the much famed high end, high power scopes we use for LRH, I find the parallax adjustment at 100 yards far more sensitive at 100 yards then at 200 yards and believe the mind boggling zero shifts in 100 yard zero’s are many times due to this factor.

    -It’s purely psychological, but confidence is everything. When I look at a 100 yard group and multiply it 10X when I think about a 1000 yard shot on a big buck, I find it much more confidence building to multiply my very tight 200 yard group 5x for the same shot. It’s also nice to see 100 and 200 yard groups the same size.

    Just some thoughts.

    Zeros: 200 Yards(left:aiming point grid cross); right 100 Yard. Prone, bipod/rear bag. These are better then average.....but..., usually shooting .25MOA with this rifle.

    5F4384CE-9A0A-4E67-A4E2-BCC7111CC372.jpeg 9EAC6228-CEAB-48EF-B14C-C3C51E799CE2.jpeg