Re: MIL and MOA Range Equations Explained & Derive
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Randyman</div><div class="ubbcode-body">great info! do any of you guys know what my scope is either m.o.a or shooters moa?
i have a nightforce 5.5x22x50 with npr2 reticle </div></div>
Randyman,
Here is a copy of a previous post I had a long time ago. This should answer your question I hope.
Bob
O.K. Here are the results of my phone calls to Leupold, Nightforce, Schmidt & Bender, U.S. Optics, S.W.F.A and Bushnell Optics.
Before I get into my great conversation with U.S. Optics, here are the results:
They all use “real” mathematical millradians, (which is 3.6 inches at 100 yards based on 6283.2 mils per circle) for their reticles.
Except for one (U.S. Optics), they also all use “true” Moa (1.047 inches at 100 yards) for their reticle spacings.
U.S. Optics, who were very helpful, say’s they make their scopes in real “mils”, but make most of their “moa” scopes in “shooters” moa (1 inch at 100 yards). They do sell a “true” moa scope also for those who want it.
Their refurbishing of the Unertl scopes also reveled that the original Unertl scopes were in “real” mils (3.6 inches at 100 yards). That is how U.S. Optics makes their scopes now.
Therefore, since my paper is for “Rifle” shooters, Snipers, Tactical shooters (and not artillery persons) I will change my paper to reflect only the “real” millradians and both “true” and “shooters” moa.
I want this paper to be a one source, definitive, accurate guide to “mils” and “moa” for shooters and to finally put the controversy to rest.
Thanks,
runner (Bob)
Inches are Inches
MOA is MOA
Don't get them confused, they are NOT interchangeable. This becomes increasingly more critical the farther out you go.
Example:
21" target * 100 / 2.5MOA = 840yards
21" target * 95.5 / 2.5MOA = 802.2 yards
The MD Master says 800 yards wink
This gives you an error of ~40 yards or the difference between your 800 yard dope and your 850 dope, in my rifle that's 3 MOA or about 25".
If your retical subtends minutes, use the MOA formula, if it subtends inches use the inches formula.
Cheers, Doc
To go along whith what Lindy said about the Loopy M1 knobs being 1" it is also wise to check any scope as dpending on the milling tolerances of the mfgr your adjustment value may be MORE or LESS.
Loopies are notorious for being .94 - .96 MOA
If it takes you 38 MOA to get to 1K via your ballistics card/program what ever it is that tells you to dail up....
MOA = 1.047" X 380 = 397.86"
SMOA = 1.0" X 380 = 380.00"
Loopy MOA = 0.95" X 380 = 361.00"
If the MOA were correct via the ballistics program and the bullet/shooter/rifle combo was perfect the SMOA would hit 17.86" low and the Loopy MOA would hit 36.86" low. I think this in a large part is where alot of people get fustrated at ballistics programs. They dial on what the comuper tells them to and then miss. They blame the computer instead of verifying what thier component parts are doing.
It's the concept of errors multiplying themselves. .047" isn't worth talking about, untill you have 38 of them stacked up then it has already become too significant to ignore.
Cheers, Doc
