Rifle Scopes mil dot is driving me crazy

[ARsR4ME]

I have a NF Mil reticle/ mil turret. I dial 3 mils from(4.0) 100 yards to (1.9)600 yards. To find out the actual drop in inchs is it

3.6 x 3 = 10.8"

3.6 x 6 = 21.6 x 3 = 64.8"

Neither work on the ballistic calculator

 

[Lindy]

Re: mil dot is driving me crazy

The second equation is correct - 3 mils at 600 yards is 64.8 inches. When you say it doesn't work with a ballistic calculator, what do you mean?

What cartridge are you shooting? With a .308, I expect a drop of about 4.4-4.5 mils at 600, depending on the bullet.

 

[ARsR4ME]

Re: mil dot is driving me crazy

50 bmg. 660 grain pmc ammo

 

[Swan]

Re: mil dot is driving me crazy

what ballistic calculator are you using?

 

[ARsR4ME]

Re: mil dot is driving me crazy

It's on my drod and says 12 moa drop. It was dead on when i did my 308 gun. But the 50 is almessed up. I did .660 on the bc and g1. So does it really drop 64" to 600?

 

[Swan]

Re: mil dot is driving me crazy

check it in JBM??

 

[rifleman0321]

Re: mil dot is driving me crazy

A 750 Amax load with a BC of 1.050, and a MV of 2660, 100m zero, 1000' ASL is down a shade over 1 moa at 500, and only 6 moa at 750 yds.

The Barrett 661gr. load has a BC of .701 at 2900 MV, and was down 1 moa at 500, 5 moa at 750 yds.

Of course your MV, altitude, temp, etc. will make some difference, but not <span style="text-decoration: underline">that</span> much.

 

[maladat]

Re: mil dot is driving me crazy

jolly roger, you might want to recheck those numbers.

There is a lot more drop than that. Even if you were shooting in a vacuum with no drag at all.

EDIT: I take it back. I played with JBM and you could get a ~1 MOA drop at 500 yards and ~7 at 750 based on a 100 yard zero if you mounted your scope 10.5 inches above the bore of the rifle.

Using standard atmosphere at 1000' and a sane sight height above bore, the numbers you give for the 661gr Barrett load yield:

100 0 MOA
200 -1.2 MOA
300 -3.2 MOA
400 -5.5 MOA
500 -8 MOA
600 -10.8 MOA
700 -13.8 MOA
800 -17.0 MOA

 

[ARsR4ME]

Re: mil dot is driving me crazy

So it is around 64" drop at 600. Okay thanks. I knew the mil dot as far as rangeing but with the way the ballistic table on my phone was coming out i thought maybe the scope was somehow different. Thanks guys.

 

[maladat]

Re: mil dot is driving me crazy

Don't count on the data I posted - it was based on the information in jolly roger's post and doesn't have anything to do with your load out of your rifle. I have no idea if the BC and MV are similar to your PMC load.

You'll need to come up with some better information on the BC of the load and MV or one of those and actual drop in the field to work out the second.

 

[ARsR4ME]

Re: mil dot is driving me crazy

It close though just from the info i have. I know for a fact that i dial 3 mils from 100 to 600. Which is 64". I also found out that the ballistic calculator has all the g numbers. After reading what they all meen i used G2 and got 10 moa which is also close to real world. Thanks for the help.

 

[Togeneral99]

Re: mil dot is driving me crazy

Per Nikons Spot-on Ballistic website
660 gr PMC load
3080 Muzzle Velocity
.434 Ballistic coeff.

With a 100 yard zero the drop is listed as -69.86"
and if my math is right....(69.86/1.047)/6 = 11.12 MOA

Now when I bought my 50 BMG the previous owner sent me some ballistics data that listed the B.C. as .684 so if this is the case then the drop would change to -58.58" or 9.32 MOA

This was all done at Nikons spot on website with a sight heaight of 2.2" 3080 MV and the two listed B.C.
Hope this helps some

 

[PittsDriver]

Re: mil dot is driving me crazy

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: nut job</div><div class="ubbcode-body">It's on my drod and says 12 moa drop. It was dead on when i did my 308 gun. But the 50 is almessed up. I did .660 on the bc and g1. So does it really drop 64" to 600?</div></div>

You stated the scope is in mills and your program in the Droid is giving you an output in moa. If that's the case, change the output. I think you can cut the math down. That's one of the reasons I prefer mil/mil, IMHO.

RT