Ballistic turret question

Discussion in 'Long Range Hunting & Shooting' started by Buzzsaw, Sep 17, 2018.

  1. Buzzsaw

    Buzzsaw Well-Known Member

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    Here is my Swarovski Z5, 5-30. I have the turret set for 143 ELDX @ 2605fps

    Say I have another load shooting the 143gr @ 2650fps

    any need to have a new turret built? Will 50fps make a difference out to 600.

    I havent got to go to my LONG range steel yet to see. Thought I would see if anyone here has "been there done that"

    [​IMG]
     
  2. el matador

    el matador Well-Known Member

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    Personally I would use the same turret. The faster load should be hitting about 4" higher at 600 yards which is between 2 and 3 clicks on a 1/4 MOA turret. Sight it in to hit 1/2 MOA low at your zero distance, or just remember to subtract a couple of clicks for longer shots.
     
  3. Canhunter35

    Canhunter35 Well-Known Member

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    Yes it will make a difference.
    Remember to factor in ur air density. Temp change from now to late fall will play a factor. If it offsets the velocity error you probably don’t need to worry, but if it enhances the error, then I would recalculate
     
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  4. Bravo 4

    Bravo 4 Well-Known Member

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    Little things can compound on each other to form large problems.
     
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  5. Bravo 4

    Bravo 4 Well-Known Member

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    As far as the "been there and done that" part of your post-
    The ballistic drop compensating turret is nothing new, in fact it's been around for decades. It however really just became popular for hunter/shooters. Don't know exactly when it came about but it has been incorporated by the Army since at least the 80's that I know of in the form of the 10X M3 Ultra riflescope adopted with the M24 Sniper Weapon System. This served as the standard issue Sniper rifle for the US Army until the M2010 took it's place in all conventional force units in 2012 (still seeing it in service with the Air Force Security Forces and some Navy Units). It's a crude system compared to modern designs but still highly effective, I have shot 1000 yard matches with an issued rifle and ammunition. With elevation in 1MOA and windage in .5 MOA adjustments, the turret was actually calibrated to different ammo than the M118LR we used. The ammo was (from best I can derive) for standard atmospheric conditions, and was not muzzle velocity specific for each rifle- just mast produced. We had to keep data books with info for each rifle and each shooting session (at least if there was any changes in conditions). As an example lets say that after zeroing at 100, one rifle's DOPE might need to be set on "6" to engage a target at 600 while the rifle next to it may need to be on 6-1 (the BDC #6 minus 1 click) or 6+1. When you changed locations or conditions you needed to aquire new drop data, or find DOPE that matches this condition and utilize that. That's where the term DOPE (drop on previous engagement) came from. Whatever you have in front of you, hopefully you have shot similar ranges/conditions/etc and can use what has already been proven.
     
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  6. Buzzsaw

    Buzzsaw Well-Known Member

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    for 600 yards, is all that necessary? I would think maybe at 1000+ but at 600 seems windage would be the biggest unknown and at that point dont shoot if not confident.

    A solid rest would be most important at this point also.
     
  7. Canhunter35

    Canhunter35 Well-Known Member

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    I was going to add: for myself, unless I’m engaging targets consistently and perfectly in similar conditions, I’m not going to attempt shots on game.
    When the rubber meets the road in field conditions whatever can go wrong always seems to.
     
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  8. Buzzsaw

    Buzzsaw Well-Known Member

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    AMEN !!
     
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  9. Bravo 4

    Bravo 4 Well-Known Member

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    Like Canhunter stated, under like conditions it's a few inches difference. Start changing environmentals and the answer is definitely! Add those few inches of drop difference to the couple-few from a big temp change and then a couple-few more to a change in altitude (baro pressure) and you have a missed opportunity or wounded animal. At 500 I don't worry so much unless I have some major changes, but past that I really pay attention...to everything.
    You are right about the wind, it is the biggest obstacle you will face. To me the drop should be a given and easy to adjust for so why not take that into account, then just focus on the one thing that can change at any given second. Would you rather be off the mark a little right or left, or off high/low plus a left/right? Or at least take one variable off the table. The more variables you take off the table the more your probability of a hit goes up, no matter what form of rest or position you are taking. If you do not have a steady position and are unsure of the shot then that, to me, is when you don't fire a round at game. If I'm unsure of a shot I don't take it, no matter the range. Like I've state in previous posts, I've turned down shots at less than 50 yards on an animal (perfectly still) because didn't like the shot. And I've killed animals well past 1,000.
     
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  10. el matador

    el matador Well-Known Member

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    Using ballistic turrets is not nearly as dicey as you guys are suggesting. Changes in atmospheric conditions do not affect point of impact very much at short to medium range. If your turret is set up for average conditions in your hunting area there's no need to compensate for temperature or altitude changes when shooting inside 500 yards.

    Just zero your gun at 500 with the turret set on 500. Any elevation errors due to your velocity change will then be 3/4" or less from 100 to 600+ yards. To me this is not worth buying a new turret.

    It would be uncommon for atmospheric changes to account for more than 1" of error at 600. I guess you could draw up some conditions that gave you 1.5 or 2" but your chances of facing such extremes would be very slight. So assuming the worst (2" of error at 600 yards) there is still no reason to buy a new turret. Because by zeroing at 500 you've all but eliminated any other errors in elevation. At ranges where your turret is causing the most error (300 yards) the atmospherics are insignificant.

    If you are shooting a temperature sensitive powder you could incur some additional elevation issues with changes in temp. But once again a new turret will not solve the problem. Its always best to learn how your rifle behaves in different environments and then decide how far out you'll trust the ballistic turret.
     
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  11. Joefrazell

    Joefrazell Well-Known Member

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    Just try and see. I doubt at 600 its going to give you much issues. After that it will though. Your only talking 3-4" roughly. Shoot and see
     
  12. Bravo 4

    Bravo 4 Well-Known Member

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    El Matador, I agree with not getting another turret for those ranges. Your technique for compensating for any changes is a good one, especially when not dealing with any other major changes. You and I were looking at it from different angles- to me it appears you were best case and me worst (as in throw in other variables).
    I will say that in a lot of places a 30-40 degree swing from morning to mid afternoon isn’t uncommon. That equals inches, then add me going from my home to a hunting spot up in the mountains and that equals inches. Those inches add up quick, as in a miss. The difference in drop is just one of those variables.
    Joe is right, go shoot it and see and record the data.

    Edited to add: I make my own BDC when hunting with masking tape, out 600 yards. Then change it when changing locations. I make sure I can still read my MOA markings to adjust for further distances.
     
    Last edited: Sep 18, 2018
  13. Tyler Kee

    Tyler Kee Active Member

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    I believe that scope is graduated in in/100 yards. Any ballistic calculator will be able to spit out corrections in in/100, MOA, or MIL. Build profiles for each load if you plan on running two different ones. Honestly, I'd pick the one that shoots best and run that though.
     
  14. Canhunter35

    Canhunter35 Well-Known Member

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    Applied ballistics offers the wraz program which offers hits percentages on the data you give it.