I'm a little confused on the MOA stuff for red dot scopes. What exactly does 4 MOA mean? And what are the "1/2" moa adjustments, etc. I'm a newb to rifles. I recently bought my first rifle. it is an AR15 from Del-ton.

It actually stands for minutes of angle. For a layman explanation, its basically fractions of an inch shift in target at 100 yards per click.

On a MIL dot it defines how big the circle is of the dot. Obviously the farther away the target is the bigger the circle will appear as if on the target. 1" MOA would be your shots all into a 1" hole at 100 yards or 2" hole at 200 yards so on. The same hold true as you go up, bigger the MOA bigger the dot on target.

the way i was told is. MOA means Minute Of Angle. and 1 MOA = about 1in @ 100yards. meaning a 1 MOA dot will cover 1in of the target @ 100 yards.



^Beat me to it^

This post has been edited by Tucker: November 3rd 2009 5:09 PM

The guys above have it right. In terms of red dots, a 4MOA reticule would be equal to a 4 inch circle at 100 yards. A 2 MOA reticule dot would be a 2 inch circle at 100 yards.

Starting to understand.

So how does a scope sighted in at 100 yards perform at 500? I know rifle shots have an arc to them right? Is there a chart somewhere to look this info up (how much higher to aim, etc?).

I'm not sure what kind of shooting I will get into. Probably something along the lines of 100 yards. So I take it a 2 moa red dot would be best for this situation. Otherwisw a 4 moa would cover up the bullseye and it would be almost like shooting with your eyes closed.

This will show you everything.

http://www.winchester.com/ballistics/

Screenshot:

WOW!! Thank you!

A 4MOA dot isn't too bad at 100. Out past that or for more precise shooting you would want a 1 or 2 MOA dot.



TS

A Minute of Angle is 1.047 inches at 100 yards. Scopes come with increments (usually) of 1/8, 1/4 and 1/5 MOA (they are commonly called "clicks" The manufactures actually figure thme in as 1/8, 1/4 or 1/2 inch movements for simplification.

Different scopes may actually move different amounts when you adjust them due to wear and other factors. It is usually best to go past the increment change and then back up into the change you want. If you need 1 MOA on a 1/4 MOA scope give it 6 "clicks" and back up 2 to load it back into the steps. (Old school but it works)

A MIL is 3.6 " at 100 yards or 3.438 MOA. Be careful when playing with this as some leads/wind drift numbers in some venues will give measurement in Mil's and when you miss the switch you will miss the target!!

Remember that these are all at 100 yards. Going to 200 doubles, 300 triples, 400 quadruples and on and on. So if you dial in 1 MOA at 100 yards (one inch ostensibly) you move the POI by 10 inches at 1000 yards. A MIL at 1000 is worth 36 inches so if you have to Kentucky windage a 1000 yard shot by holding six feet high you just hold two MILS high and drop the hammer. (this does work)

You need a good drop table and an understanding of the system but with MILS you can calculate range to a known size target, calculate the size of a target at a known range and given the target size and the range calculate the MIL abstentions as it looks through a scope. Most scopes require use of the MILS at a given power and this is USUALLY noted on the power ring on a variable scope.

The Mil Dot Master is a good tool if you want to use Mil Dots and there are several publications that cover their use.

Greg

Since you went into this detail, you ever play with the Russian POSP style scopes? They simplify all that with a built in range calculator scale and bullet drop reticule much like used on the LAW rocket. Mines a 24, the reticule is lighted with a metal toggle switch that all runs off a AA battery. Mines a 7.62X39 so not much range but it sure is fun.

Well that is if you can keep it clamped on the rail of your AK, its fun.

Tj

I've never used the Russian system. I learned the above stuff teaching snipers for the Fed. BOP. I got the extra duty because they had never had a guy that actually SHOT for fun and piled up Gold like Rumpelstiltskin !! LOL

I do the math in my head so the system works well for me since I keep a drop table taped to the bell of the scope when I am shooting PD's or on the side of the stock if I am shooting a match. A chronographed and proven drop table can sure impress the new kids learning the system.

Greg

This post has been edited by GLShooter: November 3rd 2009 7:37 PM

Yep the old crib sheet. You know that's "old school" to some of these guys. Some of these guys have PDAs which they can change the drop scale to adjust for windage or bullet type on the spot. I've even seen them mounted on the side of rifles.

That's a little too high tech for me, heck I thought getting a calculator on my cell phone was high tech.

Tj

Well, I CAN use a calculator but you know those PDA's glow in the dark? I have a data book set up with glow in the dark plastic inserts with a clear overlay drop table I can read without giving my position away.

The ability to print the sheet is great. With drop, wind deflection and come ups in MILS and MOA it is a tool to behold. I had to set down with two longtime varmint hunter guys from Kansas that were CO's from Leavenworth on their SORT (SWAT) team as M/O's (snipers) Those good old boys just swore that, "those damn tables don't work" I finally dialed their rifle back to 100 yards per the book cranked in the elevation and hit an 8" plate at 700 yards for them on the first shot. You know by the time that 2 week school was over those guys could recite that table in their sleep and turned in to the best team of 7 teams we were teaching that rotation!!

I know with your history TJ that Kentucky windage and just pure learned knowledge flows through your blood and the "old school" stuff just makes us old guys just that much more efficient.

Greg

While the others have more fully explained the details, the comment about MOA at other ranges can be easily said that every 100 yards adds another inch.

1 MOA at 100 yards should fall into a 1" circle. 1 MOA at 300 yards should fall into a 3" circle. 1 MOA at 600 yards should fall into a 6" circle.

2 MOA at 100 yards should fall into a 2" circle. 2 MOA at 300 yards should fall into a 6" circle. 2 MOA at 600 yards should fall into a 12" circle.

Naturally all that completely discounts weather, shooting skill, and ammo eccentricities.

Those numbers assume a vised gun on a bench with optimum ammo with no wind or weather.


Getting a gun into the 1 MOA range takes a bit of work. Testing factory or home loads until you get the best option. Using very high quality rifle components. Getting the right scope and properly dialing it in. And naturally the hardest part is getting the operator up to snuff. Best rifle in the world is no better than the operator.

Damn Tj and Greg... I just learned a bunch from that one original question, if you are ever in upstate NY ( and why would you be if not born here) then I'll provide the ammo you provide the clinic. I know, how big of me, but that is all I can afford right now as I'm raising/protecting two daughters (6&2) on a way too modest salary.

Rick

Rick,

Thanks for the invite. I have been to upstate NY about 300 times for about two hors at a whack. I flew in to Otisville for about 7 years on Con Air picking up Federal inmates. It is beautiful up there in the fall.

I understand that budget issue. Lots of dry firing, reloading nd selection of bulk components will go a long way in helping you stretch the $$'s. If you want to learn about long range shooting there is a disk called, "The Long Range Shooting Simulation" It costs about $40.00 and is available from Shooter Ready It is great practice for learning Mil Dots and drop tables. We use it for teaching our M'O's at the classes I taught.

I bet TJ could teach you a thing or three about all aspects of the sport and I could throw in a tidbit or two (Or at least an OPINION or two!!)

I hope we have helped you out and feel free to contact me either here or direct if you have any burning questions about hitting what you want when you want.

Greg

You have no idea how much this made me laugh. I grew up shooting guns with sights that were off, missing parts, or hell missing.

I was so bad, that in basic training I was sick on zero day and came late, so just threw some KY windage on my aim and didn't adjust my sight. I finished basic like that and qualified expert. In retrospect, I think my zero was around 300'. In those days though, I didn't know where the bullet was suppose to be, only where my aim needed to be, if that makes sense. All I needed to know was about how far that damn target was and I knew where to aim, not the why. lol


BTW, Ironically it sorta worked out. The fact my zero was so far out, we use to shoot out to 650m in those days, and I would pop the hell out of them. The target was still in my sight picture. lol

Tj

One can over think it a great deal!! It was always a fine line in teaching enough to my students to hit without blowing their minds. You do understand how Trig Functions are used in windage movement and in shooting from elevated or depressed positions don't you? That half value/quarter value windage will work but I can dial it in dead nuts with a little math. The Trig stuff always messed up students so I finally just handed them a table and told 'em to trust me!!


I too grew up not having a clue but you know there is a lot of go her carcasses in Minnesota and Wisconsin that proves you can hit them with a pellet gun at 30 yards and knock 'em stone dead with a little of Daniel Boone added in!! LOL I think that is why I like Mil Dots so much. It is the ultimate holdover tool in my bag of tricks.

Greg

Yeah, I do but don't use it. I use a crib sheet that I derive from a calculator.

I'm so lazy about this, I even load my ammo to a curve. That way I can put it all to memory and be close enough. That means my lighter bullets are often a little slower than what they could be but being able to go, for example, from a 55 grain to a 62 grain and not adjust your aiming point has some advantages.

BTW, The thing that really blows my mind is changing rifles with different optic heights. Throws it all off and back to a new curve.

Tj