Maybe I'm wrong about minute of angle....

SahaganBeta

Maybe I'm wrong and misunderstand the minute of angle concept, and if I am, please don't hesitate to correct me. Mrs. Sahagan does it all the time, sometimes even when I'm right.

But I recall reading somewhere, somewhen, that a minute of angle equaled something like one inch at one hundred yards. So that if a rifle is shooting sub-MOA, that means it shoots a grouping of something less than 1 inch at 100 yards.

Extrapolating from that value, then minute of angle would be 1/2 inch at 50 yards, and 2 inches at 200 yards. Is this right?

So, a body has a scope with 1/4 MOA adjustment clicks on the azimuth and altitude adjustments.

Would we take that to mean that at 100 yards, each click of the scope would equal a movement of the crosshairs equal to 1/4 inch? And at 200 yards of 1/2 inch? And at 50 yards of 1/8th inch?

I'm a sponge, ready to soak up truth and verity. So, teach me something here. I do appreciate it.

Sahagan

jtmarine0831

Pretty much! I have to stop myself sometimes and get the wheels a turnin'. I have so many scopes and they range anywhere from 1 MOA adjustment to 1/8 MOA. Have to stop and think which rifle I'm shooting. I think I have the most trouble remembering increments when I'm adjusting my rimfires( usually 25 and 50yds). I think I think too much![:p]

sandwarrior

SahaganBeta,

You are right on with the math sir! If you continue on though you will find that since a MOA is actually 1.047" at 100 yds. you will find that one MOA at 1000 yds is 10.5(or really 10.47)". Not that anyone has ever really been that accurate in the past ever. The distance just keeps adding up the total distance you will need to judge.

SahaganBeta

Thanks guys;

I happened to find, just last night, a GUNS magazine article that explained that critical difference between MOA and inches, as a result of the .047 little extra.

That also helps explain why, in sniper movies, the spotter/sniper spends time doing math on a notepad before taking that important shot. And yeah, at 1000 yards, I can see how 10.47 inches could spell 'miss' real easy, although at 100 yards, for most of us, it would likely be negligible.

Again, thanks!

Sahagan

sandwarrior

SahaganBeta,

You know for all intents and purposes, no one has ever been accurate enough to make the .47" matter at 1000 yds.

However, JustC recently posted something of real interest regarding your original post. Rather than measure in inches and have your come ups in inches keep your come-ups in MOA. That way you have no conversions to make. If you have a target scope then you probably have MOA to come-up to. At 1000 yds., rather than have 400 something inches to come up you have 40 something MOA(depending on caliber and zero). Much simpler when adjusting scopes.

SahaganBeta

Yeah, that's the same conclusion the author of the GUNS article came to. However, it's apparently vastly important that both shooter and spotter use the same nomenclature and measuring standard.

I'm normally shooting at distances less than 100 yards....so it isn't an issue yet. But, I'm hoping to continue working at it until I can get the maximum distance possible, out of a handgun, and at some point, MOA will become an issue.

Thanks!

Sahagan

Old Gunny

By any chance did you guys see either of these movies- Jake Ghylendal plays a USMC sniper in "the sandbox" and calls out his ETR in feet, not in meters. Hey the military went metric with the M-14 and M-60 NATO 7.62x51. Barry Pepper plays a WW11 Ranger sniper in "Saving Pvt. Ryan"- used three different detachable scopes on his l903 sniper rifle, and at the end, when they hook up with Pvt. Ryan and what's left of his 101st. A/B squad, he gets into a church tower, and left handedly cranks off 8-count 'em-8 rounds from a 5 round capacity Springfield. I have a Springfield Armory NM (l938) not a l903-a3 set up with Unertl 10X scope, leather check rest and the cone style flash supressor later used on the M-1D Garand sniper rifle. We are at the local gun club on the 200 yard range, when some "Barney Fife" in uniform comes over to watch us shoot- then tries to bust me for having an illegal silencer. I told him "Depitty" you lay under my bench so's your ear can hear the silencer at work whilst I crank off a round for you- almost though this numbnutz was gonna do it, but his buddy talked him out of it. Darn..

jonk

Right. MOA is derived at from the idea that in a circle of 360 degrees, each degree has 60 minutes (and each minute has 60 seconds). Using your body as a hypothetical center point and drawing a hypothetical circle on the X and Y axes 200 yards in diameter, i.e. 100 yards from you to the target along the radius, 1/60 of 1 degree is equal to approximately 1 inch- a tad more as noted above. Hence for a circle 200 yards in diameter, or a range of 100 yards, one minute of angle is 1 inch; for a circle of 100 yards or a range of 50, it is half an inch, etc.

If you're half good with geometry (or at least with google! [:D]) and have a compass and protractor for visual aid, you can work this out to your own satisfaction.