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akluvr
February 8, 2000, 04:41 PM
I know, this is a very stupid question but, I've never had anyone tell me what this means before. What is MOA? I know it stands for "minute of angle", I think. But what is that? I hear people all the time talking about shooting 1 MOA or such and don't have a clue what size grouping this makes. Pleae help a newby here, thanks in advance!!! http://forum.arstechnica.com/forum/ubb/smileyshot2.gif

[This message has been edited by Schmit (edited February 08, 2000).]

jwong
February 8, 2000, 04:46 PM
1 MOA = 1" at 100 yards... There are no bad questions... So don't be afraid to ask around here...

akluvr
February 8, 2000, 04:53 PM
Thanks jwong, I appreciate it. My knowledge is already growing from this site.

Rich Lucibella
February 8, 2000, 05:05 PM
akluvr-
In addition to the MOA designation as a way of talking about general accuracy, the concept is critical in zeroing most scopes made for the US market. Lemme see if I can do this right....if I get in trouble, someone here please jump in.

Since most scopes are calibrated with click adjustments which equal 1/4", 1/2" or 1" at 100 yards, they are actually calcualted in MOA. (To think thay are calculated in "raw" inches leads to frustration).

Example with a scope calibrated for 1 click= 1/4" at 100 yards:

Quiz #1:
You do an initial zero at 50 yards. The shot impacts 1 inch right. How many clicks left should the scope be adjusted?

The intuitive answer for many, including me, of 2 clicks would be wrong. Since 1" off at 50 yards will mean 2" off at 100 yards, you need to adjust left 8 clicks.

Quiz #2:
You are zeroing a rifle for bullseye at 200 yards. Your group hits 1" high at that distance. How many clicks down should the scope be adjusted?

Again the intuitive answer, 8 clicks is wrong. The correct answer is 2 clicks. (8 clicks would drop impact 2 inches at 100 yards, but 4 inches at 200 yards).

OK, so I've answered a question that hasn't been asked! I always wanted to see if I could explain that common mistake. (Right now, the military types, like Mykl and Gunny, are scratchin' their heads sayin' "Well, duh?!". That's because this stuff comes second nature to them. OTOH, just ask one of 'em to balance a checkbook!!! ;) )
Rich

Schmit
February 8, 2000, 08:33 PM
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Right now, the military types, like Mykl and Gunny, are scratchin' their heads sayin' "Well, duh?!". [/quote]

Hence the title "Minute of ANGLE"

Balance? Checkbook!? Huh?

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Schmit
GySgt, USMC(Ret)
NRA Life, Lodge 1201-UOSSS
"Si vis Pacem Para Bellum"

Dorcas
February 8, 2000, 09:33 PM
1 MOA = 1/60 of 1 degree = 1/21600 of a circle.

bkm...

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Anyone worth shooting, is worth shooting twice...

Art Eatman
February 8, 2000, 11:23 PM
akluvr, Dorcas' answer is the most accurate, but it's so near one inch at one hundred yards that "hit don't make no nevermind". At least, not for anything you can carry without wheels or shoot from the shoulder.

50 years ago, anything with iron sights which stayed around two to three moa was a "good huntin' rifle". Scopes kept folks into one to two moa, and the benchrest guys were working pretty hard to keep 10-shot strings inside one moa. Ah, those "flyers"!

FWIW, Art

Zensho
February 8, 2000, 11:24 PM
1 MOA or 1.047" @ 100 yds. Center of circle being origin of projectile meaning .006 deviation at the end of a 20" bbl = to 1MOA.