Problem with calcs for 4dof and strelok

[Maris Piper]

Have you looked at powder temp? It can make a huge difference. If its a hot day and the bullets have been out in the sun - or in a hot car, but your app is set at an average temp you can be 100+ fps off.

 

[SammySTW]

I'm curious. I have never seen a MOA turret on a mil scope and do not understand how the mechanicals would operate. Do you know if the clicks "lined up" assuming 4 clicks for 1 MOA and 10 clicks for 1mrad? Would that show up as a misalignment on the reading on the turret? If so, could that be checked before mounting the scope?

It's easy, pull your turret off just like you would to set it to "0", and put a different turret on, it doesn't affect the mechanicals, it's only different labels which would be wrong. It definitely sounds like Vortex accidentally put turretswith MOA labels on a scope with MIL mechanicals, the math adds up right.

 

[jdavistx]

Vortex viper HS-t 6-24

You didn't specifically mention if you have shot this scope on another rifle, or I missed it. If so, what were the results under similar conditions?

 

[SammySTW]

If you're dialing 12.35 "MOA" for hits at 905 yards, that is 49.4 clicks. Try switching your 4DOF app into mils and see what it tells you to come up, see if it tells you to come up 4.9 or 5.0 mils.

 

[jdavistx]

It's easy, pull your turret off just like you would to set it to "0", and put a different turret on, it doesn't affect the mechanicals, it's only different labels which would be wrong. It definitely sounds like Vortex accidentally put turretswith MOA labels on a scope with MIL mechanicals, the math adds up right.

If that's the problem, shouldn't even have to change turret cap. There will be visual mis-alignment. 10 clicks from zero would be 1 mrad (3.6" @ 100 yds) but read 3.6/2.6 = 1.4 MOA.

 

[SammySTW]

If that's the problem, shouldn't even have to change turret cap. There will be visual mis-alignment. 10 clicks from zero would be 1 mrad (3.6" @ 100 yds) but read 3.6/2.6 = 1.4 MOA.

That's not what I was talking about

 

[jdavistx]

Sorry, guess I'm a bit slow. Please explain.

 

[SammySTW]

Sorry, guess I'm a bit slow. Please explain.

If the scope is in mils, each click of the turret gives you 0.1 mil of adjustment. If Vortex accidentally put the wrong turret on the scope (turret reads MOA, click value is MRAD) you would think you're dialing 0.25" per click when you are really dialing 0.36" per click, at 100 yards. If this is the case, you would most definitely need to change the turret cap to one that reads mils to match the click value.

 

[BCJ]

Well I have a odd one for everyone. I have been trying to do some long range shooting using the hornaday 4dof and strelok apps. They have both consistently been way off for my gun. See details below. Any help is appreciated.

4dof says come up 17.93 moa and 0.48 left. Actual hits at 12.35 up and 1.25 left.
Range: 12" steel. 905 yards at 8 degrees down. 0 wind. 68% humidity. 55 degrees. Elevation 4100. Pressure 28.5

Rifle: Savage 10t-sr 300win mag.
26" barrel with 1/10 twist.
178 gr eld-x hornaday 3025fps
Zeroed at 200 yards .3 moa hits constantly

I tried it at 675 yards too. It said to some up 8 moa. Actual hits at 5.25 moa.

Your base line is not correct then on the Hornady App. Check all of your inputs regarding your gun, establish your Zero Angle and Axial Form Factor. Bad input creates bad output.

 

[PNWdude67]

Yes. Says come up 17.93. actual hits at 12.35 ish.

But is your App set for your rifles 200 yard zero. Most apps default to a 100 yard zero

 

[JAYgs8163]

We're all kind of ****ing in the wind until he gets back from the range.

 

[John Klingenberg]

I do this. I chrono my load, shoot at target to get the actual drop at 400 and then put my numbers in the app and adjust bc until it matches. So far it's worked pretty good.

 

[338 dude]

I can certainly give it a try. Here a question. When it asks for the sight height on which end of the scope do you measure this? since I have a 20 moa rail on the gun the front and back are different.

It won't make that big a difference to test my theory if your scope height is say 2 inches now move it to 1 inch and check the difference that it tells you

 

[338 dude]

I don't know if I've ever seen a barometer that goes below 28. It would have to be more like 2 to make a difference like this anyways. The current official barometric pressure at my home is 29.5 at 2200 feet.

Are you sure you are set for barometric pressure or possibly station pressure