Zeroed at 100 but shouts 4” high at 200
- Thread starter tbroz
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Now imagine his first zero was 100, how high would he be at 200?
To know for sure what his real zero is, what's his scope height, BC, velocity, pressure, etc.
Then run the calcs until you get the 4 inches high at 200 and that would tell you what his 'actual zero' is.
Scope is 2" high. I used S & B 300 match and one reload was 300 AB with 91gr of h1000. Sorry I don't have anything to check the speeds yet.
Maybe I missed your answer, but as others have asked, what kind of groups are you seeing at 200 yds? That'll help determine the reliability of the data. What's happening out there? Shots stringing up or are you getting 3 or more shots consistently 4" high...?
Shoot from bags (skip the shooting rest) and see if you get the same result. Maybe show us some photos of your setup and targets. 
lancetkenyon
Well-Known Member
So...where is his "second zero" if the "First zero" is at 100....
His "first zero" is actually at about 90 yards, his "second zero" is at about 110 yards. 200 SHOULD be about 2.5" low.
The further out you go for the "second zero", the "first zero" moves CLOSER to the shooter.
Unless....the OP is shooting something like this...then maybe.
Not sure if just the 200 yard groups or all groups at both distances are "a little high and a little left"
Your zero whatever it is has to be perfect, it can't be a little higher or left or right. It has to be perfect in order for any predictions to work.
Definitely confirm (adjust) your zero as close as it can get to perfect.
At 100 they are perfect. The group touches or almost. At the 200 it's 4" high and about 1/3" to the left. The group does open up just alittle which is expected shooting farther out.
lancetkenyon
Well-Known Member
This is the only way I can see the trajectory work out to be zero at 100 and 4"+ at 200. If you have a 9" above bore sight height...which I am sure you don't. Actual zero distance (second zero) would be 363 yards.
This is based off a 338 Edge pushing a 300 Hyb @ 2850fps.
This is based off a 338 Edge pushing a 300 Hyb @ 2850fps.
Straight Shooter
Well-Known Member
Have someone else shoot the dang gun.
lancetkenyon
Well-Known Member
My ballistic app won't let me run these numbers, but to have a 100 yd zero and be 4" high at 200, and have a 2" above bore height scope mount, maybe if you were running the bullet at 15,000fps? I doubt that. Unless you got a new hand held rail gun from the US Navy and DARPA.
Bad parallax? If you have a bad parallax, your reticle will move in relation to the target depending on your eye position, meaning you are not actually aiming where you think you are aiming. But to cause 4" @ 200 (or 2" @ 100), you would have to be moving your cheek weld and eye box a TON and have the parallax be WAY off. I don't see that happening.
The other thing I have seen, but not as consistently as to shoot 1/2 MOA @ 200 yards, is hitting a sling stud or Picatinny rail on the bottom of the stock during recoil and jumping the rifle up.
One other thing, but this would be extreme, is barrel harmonics and whip. You would have to be shooting a wet noodle barrel to cause this.
Combo of all 3? Maybe. But again, not to get consistent groups off.
Did you dip your bullets in Redbull? Redbull gives you wiiings? Maybe the bullets are flying away?
Bad parallax? If you have a bad parallax, your reticle will move in relation to the target depending on your eye position, meaning you are not actually aiming where you think you are aiming. But to cause 4" @ 200 (or 2" @ 100), you would have to be moving your cheek weld and eye box a TON and have the parallax be WAY off. I don't see that happening.
The other thing I have seen, but not as consistently as to shoot 1/2 MOA @ 200 yards, is hitting a sling stud or Picatinny rail on the bottom of the stock during recoil and jumping the rifle up.
One other thing, but this would be extreme, is barrel harmonics and whip. You would have to be shooting a wet noodle barrel to cause this.
Combo of all 3? Maybe. But again, not to get consistent groups off.
Did you dip your bullets in Redbull? Redbull gives you wiiings? Maybe the bullets are flying away?
I will but this won't happen for a bit. Live in Ont Canada and a bit of a pain to shot where I live did all the testing when I was moose hunting up north and realized the issue when shooting farther out. And yes I should have tried 300 but did not.
lol with the red bull. But I will check the sling screw it did line up with the rest. And some one else told me if the parallax has moved in the scope it will be off. Bushnell also told me the same but need to new scope and go through it all again to really see
