View Full Version : Accuracy: How much is enough?
mkmckinley
02-24-10, 05:15
How much precision do you need out of an AR for, say, 3-gun or multigun competition. I know we'd all like to be shooting .25 MOA rifles all the time, but is there a "good enough" to be competitive for 3 gun? As a side note, supposedly Colt's magic number is 4 MOA or less for M4s with green tip which seems trajically imprecise. I guess they're counting on us t use accuracy by volume.
How much accuracy you need will depend on distance to target and target size. How much accuracy you can achieve will depend on how mechanically accurate your carbine is, your skill level, the optics you are using (you can't hit what you can't see), ammo, etc.
Many guys get wrapped around the axel about mechanical accuracy and factor in "practical accuracy"
This article may give you some food for thought:
http://www.03designgroup.com/photo/which-carbine-is-more-accurate/icon-which-carbine-is-more-accurate.jpg
03designgroup | Which Carbine Is More Accurate http://demigodllc.com/icon/extwh3.png (http://www.03designgroup.com/technotes/which-carbine-is-more-accurate)
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Robb Jensen
02-24-10, 07:43
How much precision do you need out of an AR for, say, 3-gun or multigun competition. I know we'd all like to be shooting .25 MOA rifles all the time, but is there a "good enough" to be competitive for 3 gun? As a side note, supposedly Colt's magic number is 4 MOA or less for M4s with green tip which seems trajically imprecise. I guess they're counting on us t use accuracy by volume.
For the vast majority of 3 gun any gun that can do at least 2MOA will do fine.
M855 is very inconsistantly accurate ammo. It was designed for belt fed machinguns. XM193 isn't much better but pretty much any 55gr other factory ammo will be more accurate. I've had some Wolf ammo that was more accurate than XM193.
Most decent free floated ARs shoot 1-1.5 MOA with good ammo, however a lot of this has to do with good optics and mounts, a great trigger and a good shooter. Premium barrels will typically do 1/2 of that.
The majority of the non-SPR/DMR type AR15/M16 ( Colt, Bushmaster, Stag Arms, Remington etc. ) and HK416 rifles I have fired and seen, have usually grouped c. 0.7 MOA - 2 MOA, with various commercial loads from 52gr up to 69 gr.
4MOA being tragically imprecise? Not so much. At 400 yards, it amounts to 16 inches, which is still small enough to cover a torso. That would be a disabling hit, which is good enough. Goes back to the combat studies, most effective shooting is within 400 yards, a non participating soldier is the goal, it doesn't take a lot of caliber to do it.
Ergo, intermediate assault rifles on the battlefield. It's not really different than LEO/self defense - the point is to get the other human to stop being lethal toward you. It's not always a requirement to drop them dead right there.
In range competition, things can and will be tightened up to discriminate against shooters with less developed skills. It's the whole point. That's not bad, it is expensive to achieve in a standing army. Adding an optic can get better accuracy at a much cheaper cost.
Does that make milspec guns with optics a losers choice, or is shooter skill more important? Americans tend to buy much more capability than they have expertise to use - just look in the nearest auto salvage yard. If they actually shoot enough to know it's the gun, then it's time to fix something.
Point being, the obsession with MOA is like wearing a watch that keeps time to the second a year. Nobody really needs it, they just like knowing it can.
Those that don't care buy imported piston action Combloc repros. :D
4MOA being tragically imprecise? Not so much. At 400 yards, it amounts to 16 inches, which is still small enough to cover a torso. That would be a disabling hit, which is good enough. Goes back to the combat studies, most effective shooting is within 400 yards, a non participating soldier is the goal, it doesn't take a lot of caliber to do it.
The average human torso is 12" (not 16") , and of that 12", only 8-10" is an effective stopping/kill zone.
With that in mind, a 4MOA gun would NOT cut it. You'd only get hits on an average human being 75% of the time, and of those shots, only 75% (or 1/2 of all of your shots) would be effective. How is that in the least bit accurate? You have a 50% chance to stop your target. You'd have just as much luck flipping a coin and using a .1 MOA sniper rifle if it landed on "heads.' Even a 3MOA gun, by comparison, would still only yield effective shot placement 75% of the time. Taking the human factor out of the equation, 2MOA past 300yds is the least amount of accuracy one should go with, as anything less accurate will not be able to place shots within the torso's vital organs area.
Also, most engagements happen under 150yds, not 400yds.
A better question is how accurate are you? a mechanically 1/4 MOA gun with a 6 MOA shooter is still a 6 MOA group. Which is pretty miuch the .mil standard.
Hitting an 8 inch plate at 400m on a flat range with no stress is great. awesome in fact. but for combat, 4 MOA is very good. I havent seen much better than that. I mean, theoretically,
A better question is how accurate are you? a mechanically 1/4 MOA gun with a 6 MOA shooter is still a 6 MOA group. Which is pretty miuch the .mil standard.
Correct me if I'm wrong (I'm not service yet, at least until Jan 2011), but the mil "standard" is roughly 2 MOA - qualification is hitting a 12" torso knockdown target at 600yds.
For the Army grouping and zeroing is done in a 4CM circle at 25 meters. The Qual goes to 300 meters.
So 4 Cm converts to 1.6 inches at 25 meters. Which is huge down range. It is "man sized" at 300 meters. that is the standard.
i dont know about the Marine Corps. Maybe someone can jump in. Vickers uses small targets in his training knowing that under stress accuracy decreases.
Yes if your gun can only produce groops that are 4-5 MOA it is broken, but mostly it is the shooter
mkmckinley
02-24-10, 14:51
A better question is how accurate are you? a mechanically 1/4 MOA gun with a 6 MOA shooter is still a 6 MOA group. Which is pretty much the .mil standard.
I know how accurate I am, why would I need to ask that? In my unit a 6 inch group at 100 yards would get me laughed off the range. I know the shooter skill side of the equation, I want to figure out how much rifle I need for 3-gun from people who are involved in the sport.
4 MOA from the rifle itself is inadequate for combat. I forget exactly how to do the statistics but a 4 MOA shooter with a 4 MOA gun doesn't shoot 4 MOA. The error's stack on each other. He ends up having like a 90% probability of shooting in about a 7 MOA circle. That is not good enough for engagements at distances above 200m, especially considering people don't usually expose their whole torsos in an engagement. The engagement distances we're seeing in Afghanistan are generally 200-400 meters right now, often more.
Tirod, I don't know what your experience has been but when I'm shooting at someone 200+ meters away I wish for as much accuracy as I can get and I want to deliver as many foot-pounds as I can. I shoot M118LR 7.62 at bad guys. Having fun back home is different; what I'm learning from this thread is how much accuracy I need for competition.
Skyyr, What MOS are you going for?
GotM4 gave you a good answer, MK. Sorry to hijack your thread. It felt like it was going to end up a "check the chart, go to a class" thread.
Skyyr, What MOS are you going for?
Marines OCS Flight Program. Based on my upcoming PFT and subsequent score, I'll know if I got one of the Dec 2010/Jan 2011 OCS slots.
mkmckinley
02-24-10, 15:14
Hey no problem, we're having a good discussion here. I brought up the whole 4MOA thing in the first place.
4moa puts us on a target within the Rifleman's quarter mile but not much else. I am currently looking at was to improve this across the board. But the M4 has a 3 MOA tolerance, and our ammo has 3 MOA tolerance, so cant ask much more than that.
How much is enough? As much as you can get. I have never heard of a rifle being sent back to the factory becasue it was too accurate.
Just switching from FMJ to OTM or even soft points can cut your groups in half. Then you can go with free float handguards, high powered optics, and fancy triggers to shrink it more if you like.
Just my .02,
LeonCarr
How much is enough? As much as you can get. I have never heard of a rifle being sent back to the factory becasue it was too accurate.
Just switching from FMJ to OTM or even soft points can cut your groups in half. Then you can go with free float handguards, high powered optics, and fancy triggers to shrink it more if you like.
Just my .02,
LeonCarr
true, though i'm sure plenty of rifles get sent back for being unreliable-ie overly tight chambers.
seems most AR's will do 2MOA or so with half decent ammo. i consider that to be quite good.
Chris Rhines
02-24-10, 18:43
For 3-gun competition, the default long-range target is usually a 10" diameter plate (MGM Flash Target.) At large matches, you'll be engaging those targets out to 400 yards, maybe a little more. That's about 2MOA. Then you'll need a little slack to account for your own ability under field conditions.
In my opinion, a serious 3-gun rifle/ammo/optic needs to be able to get 1.5MOA out to 500 yards, and 1MOA is better.
-C
How much precision do you need out of an AR for, say, 3-gun or multigun competition. I know we'd all like to be shooting .25 MOA rifles all the time, but is there a "good enough" to be competitive for 3 gun? As a side note, supposedly Colt's magic number is 4 MOA or less for M4s with green tip which seems trajically imprecise. I guess they're counting on us t use accuracy by volume.
For competition, I would look for something around 1moa.
Four moa isn't Colt's spec. It's the US Govt's.
C4
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