Understanding MOA and Mil Values

[parrotheadkjc]

I have a silly questions here, but I want to make sure I understand MOA values and Mil Values.
I have a scope with the following adjustments: 1 click = 1/4" @ 100 yds, so with that in mind, at 400 yds, 1 click = 1"
Am I doing the math right?
Example: If I have 20" drop at 400 yds, I would would need to dial in 20 clicks (or 5 full number values on the turrent) of adjustment on the elevation, right?

Now for Mil values: 1 mil = 3.6" at 100 yds, 36" @ 1000 yds so at 400 yds, 1 mil = 14.4". Correct?
So if using the the same drop in the above example, I would hold over approximately 1.4 mils on my scope, since 1 mil =14.4" @ 400 yds


Thanks for the help. I am trying to make a range card for my varmint rifles and I want to make sure it is right.

 

[dreever]

Depends. Is your scope 1 click = 1/4 inch at 100 yards, or is it 1 click =1/4 MOA at 100 yards? Somewhere in the specs it should tell you.

1 MOA at 100 yards = 1.047 inch so your clicks would each be worth .26175 at 100 yards.

As to mil's scopes with Mil adjustments usually are .1 mil per click

 

[parrotheadkjc]

I doubled checked and you are right, it is a 1/4 MOA at 100 yards.
I will have to adjust the math for the 1 MOA = 1.047", but the ratio portion of my calculations is correct, right?

the the second part - mil adjustments did not apply to what I was asking.

What I was asking was, that IF, in my original example, 1 mil = 3.6" @ 100 yds, therefore 1 mil = 14.4" @ 400 yds. With a 20" bullet drop, 20"/14.4" = 1.4 mils (round number) hold over.

Thanks Again

 

[sscoyote]

"What I was asking was, that IF, in my original example, 1 mil = 3.6" @ 100 yds, therefore 1 mil = 14.4" @ 400 yds. With a 20" bullet drop, 20"/14.4" = 1.4 mils (round number) hold over."

That's exactly right. I always use the most basic form of the mil-ranging forumla to calculate rangefinding and downrange zeroing with any reticle/turret--

tgt. size (") x range of reticle subtension meausrement (usually 100 yds.) / reticle subtension (") / quantity of "gap" tgt. occupies (decimal equivalent) = range (yds.)

For downrange zeroing substitute total bullet drop for tgt. size (it's a dimension just like tgt. size), and turret clicks where reticle subtension is. or keep the reticle subtension if using one.

Example 1)-- 20" total of bullet drop at 400 yds. using the milliradian--

20 x 100/3.6/x=400

x= 1.4 mil. (would be the same for rangefinding with this 20" tgt. size using the mil reticle, but range would then be the unknown, of course).

EX. 2)-- 20" @ 400 yds. using main 1.0 IPHY marks on the turret-

20x100/1/x=400

x=5.0 IPHY

EX 3)-- 20" @ 400 yds, using main 1.0 MOA turret (remember 1 MOA=1.047 IPHY)--

20x100/1.047/x=400

x=4.8 MOA