What should I consider for improving my AR15's accuracy?

[Kimio]

I know there are several things that I should look into as I gradually build up my AR15, of course most of the accuracy is dependent on the skill of the shooter, I'd like to know more about what goes into make a really accurate AR.

Currently I'm using a stock M16 style Stag Arms model 4 with a 1:9 twist 20" barrel with an A2 stock.

From what I've researched there are many things that can affect the rifles accuracy.

Fit and finish: If there is play between the upper and lower reciever this can hinder accuracy

Free floated barrel: contact between the handguards and the barrel can adversely affect the barrels harmonics.

Stock selection: As I understand it, a fixed stock helps with accuracy as well (Perhaps due to the ridgidness it provides as opposed to collapsable ones?)

Barrel thickness: The hotter the barrel gets, the greater it distorts the trajectory, so if I understand correctly a heavy grade barrel would be nice.

Trigger: gritty or "Stagey" triggers can adversly affect accuracy as well if I recall, a smooth crisp trigger pull will help in this aspect.

Finally: Ammunition. Good match grade ammunition will help you attain the most out of each shot in a well built platform.


Is there anything else that I may have missed? Points I may be misinterpreting and so on.

Comments and advice would be appreciated.

[darkgael]

If you want the gun to be match accurate, make it like this one:

[Sweet Shooter]

I'm new to ARs but not to rifles generally. I don't think the FF tube is necessary. On rifles with wood furniture maybe—but the AR? I don't think so.

I don't think the Delta Ring is a good design. I do think that the relative looseness of the two piece M4 style guards (or any guards that move) are a problem. A tight fitting two-piece quad-rail takes any of the "play" out, and I think may actually be a benefit.

Even a FF tube flexes about and actually applies effective leverage—in the sense that it is capable of producing amplified force—to the overall geometry of the rifle in an inconsistent way. There is enough variable movement in the rifleman that is only compounded by anything on the rifle that moves or flexes.

Matching ammo to the barrel is huge I think, The orientation of a Cup/Core projectile has a huge effect, and a bullet being driven backwards (FMJ) has a more irregular base resulting in a less stabilized spin than one being driven "open-tip forwards" (HP). With a good crown on the barrel a flat base bullet will be best. I believe that a boat tail on an FMJ is a contradiction in terms and only serves to lengthen the projectile requiring a tighter twist... it is not a make good on a bad crown. However it will raise BC.

The sighting system it's self and perhaps more importantly the way we attach it, is probably the biggest robber of accuracy. If you're looking for SUBMOA all the time, then a scope is obviously called for. The ability to mount the rifle consistently without canting it (even at the bench) is also imperative with sights that are this far up from the bore.

2c
-SS-

[sailskidrive]

Within 100 yards, a good trigger makes huge difference. Once you reach out to 200 yards and beyond good ammunition, quality glass, and barrel come into play.

[stevedscross]

how much accuracy do you want? I have a non free floated 16" mid leanth heavy barrel without crome that will shoot 3/4 - 1 MOA all day long. It will hold 2MOA with wolf ammo. So I would say get a good trigger, good (better yet great) sighting system, use quality ammo and you can have a 1MOA rifle all day long.
NOw that was accuracy, however if you are looking for bench rest accuracy for a Match than that is a whole new ball game. First get rid of any 5.56 chamber and get a 223 wyle chambering. free float that barrel, and make sure the barrel is a match grade from a great maker. I have Larue 18" 1/8 twist that shoots great, but is also cost more than the 16" mid. Speaking of twist that is next you need to know the range you want to shoot at, say you are only shooting 200 , you have more choices than if you want to do 1000 meter things. the faster the twist IE 1/7", 1/8" will shoot better with the heavy 75grain, 77 grain MK262 BTHP. now they will still do fine with the junk 55gre wolf shooting at milk jugs, but I don't know to many people that put that time and money into a rifle to plink with (Though I do know few).

After all that make sure the stock fits you. The leanth of pull needs to be correct so you and the rifle will fit togeathe. Next get the trigger that you like the best, not don't just go for expensive because some match trigger take some time to get used to and you might not like them. As a note you should remembe that the crome lining on AR15 barrels is for durability not accuracy. A stainless or non cromed barrel will out shoot a cromed barrel if all other things are equal. Most companies that sell stock Ar15's sell them with cromed barrels because for plinking, police partol use, and self defense they want the barrels to last longer, not be perfectly accurate.

Hope I helped.

[darkgael]

I don't think the FF tube is necessary. On rifles with wood furniture maybe—but the AR? I don't think so.

That may depend on your intended use. For target shooters using a sling, the free float tube isolates the considerable sling pressure from the barrel. As issued, the sling is attached, essentially, to the end of the barrel. Slinged up and shooting prone, that pull makes the barrel flex and alters the POI in an inconsistent way.

how much accuracy do you want? I have a non free floated 16" mid leanth heavy barrel without crome that will shoot 3/4 - 1 MOA all day long. It will hold 2MOA with wolf ammo. So I would say get a good trigger, good (better yet great) sighting system, use quality ammo and you can have a 1MOA rifle all day long.

No argument about the trigger. About the groups....how are they being shot? From the bench? From position using a sling? The whole point of free floating the barrel is to remove sling pressure.
Pete

[Sweet Shooter]

@darkgael... my point about the FF tube is that I believe it is capable of potentially producing more leverage on the rifle as a whole.... not the barrel in particular. I understand that it has less direct contact with the barrel. I'm talking about the principal of the lever.

In a wood stock where the stock material is unstable I'm down with it. But on a tight AR. I don't buy it.

But what works is what works...

-SS-

[Kimio]

A little bit of both, I'll be practicing while at the bench but I'll also be going out into the desert and shooting at targets on the move. My goal is to eventually get good enough to try and go to competition shooting.

[The Long Shot]

You should also check the gas block to barrel fit, you don't want something wiggling around affecting barrel harmonics. And check your barrel extension to receiver fit. Both of the above can be solved by some blue loctite. You can also true the receiver; Some people swear by it, but if you stick to high quality parts you should be fine.

If there is play between the upper and lower an accu wedge and o-ring won't help. Both can be compressed. I'd recommend you install the armalite NM takedown teams. If you are really after accuracy you can glass bed your upper to your lower, but that'll make it where you can only use that lower with that upper. If you have play in the front pivot pin you can get out the good ol' file, file away a bit on both sides, and use some glass bedding compound on one side of the front pivot pin area on the lower. Only do the above if you are trying to get the very last bit of accuracy out of your AR.

[darkgael]

Sweet:

my point about the FF tube is that I believe it is capable of potentially producing more leverage on the rifle as a whole.... not the barrel in particular. I understand that it has less direct contact with the barrel. I'm talking about the principal of the lever

Understand the principal of the lever. Don't see how the free float tube could produce more leverage than the stock mounting point.
Kimio:

I'll be practicing while at the bench but I'll also be going out into the desert and shooting at targets on the move. My goal is to eventually get good enough to try a

In all that shooting, do you ever use a sling to stabilize the gun? Do you shoot from prone using a sling? If not, then you may well not need a free float tube.
Pete

[Kimio]

I'm trying to practice with and without a sling, I've invested in one of those single point slings to help me in the standing position to improve my accuracy, but I don't think I can count on having it all the time.

Three gun competitions are what I'm looking to get into as well.

[darkgael]

Kimio:

I'm trying to practice with and without a sling, I've invested in one of those single point slings to help me in the standing position to improve my accuracy, but I don't think I can count on having it all the time.

Three gun competitions are what I'm looking to get into as well.

I am not familiar with the requirements of three gun competitions involving a rifle. It may well be that a free floated barrel is not as important as it is in HP Service Rifle matches.
As to offhand shooting and slings. In HP matches, the sling is not used while shooting offhand....notice the shooter in the earlier picture.
Pete

[oryx]

I focus on chamber/ barrel, ammo, sights and trigger. For sling shooting such as in highpower - def a FF hand guard.
Having a well cut chamber and quality barrel with matching ammo is extremely important to the accuracy. So many chambers are cut with reamers that are used for mass production. They wear out, get sharpened and produce a range of tolerances and quality.
A good trigger that allows manipulation without moving the gun is also critical - a good 2 stage trigger (Geiselle) is what i prefer for precision shooting.
Precision sights with good repeat ability is also important when changing distances

The only only other recommendation I would make is the use of a bore guide when cleaning so you don't wreck that well cut chamber. proper cleaning methods, tools and solvents go a long way to keeping it accurate.

[jackpine]

first tighten up the loose nut behind the trigger and then focus on gear. In other words after you have 1000 rounds thu the rifle you hopefully know what you and your rifle together can do and then maybe think about adding pieces-parts. If you need help getting your rifle skills down sign up for an appleseed marksmanship program in your area.

[eric75]

The sling is not used by the shooter in the picture because it is prohibited by the rules of the competition. In prone and seated you bet he's using that sling. In fact he's pulling on that sling so hard that an non-free floated barrel would change POI by at least an MOA (and that is with the front sight moving with the barrel). Total leverage is the same; but with a free floated barrel, only the upper receiver is bending, not the barrel and upper receiver. Admittedly the sling is least beneficial for standing, but it will still be an aid to stability, especially without the shooting coat and mitt.

The single point sling is a completely different animal, as 3 gun competition is completely different from CMP competition. I'm not as familiar with single point slings, but I perceive they are more for carrying and being quick to maneuver the gun than they are for precision marksmanship. They do help stabilize the positions somewhat when it is put to that use. Because the sling attaches to the back of the lower receiver only, sling tension is not as much of a concern, but competitors still prefer a free floated barrel. To start out in three gun you would probably find it's more important to understand your sights and bullet trajectory than to spend the extra money on upgrades to your equipment.

My recommendation is to learn the fundamentals of shooting. When you know how to make an ordinary rifle perform, then you will know a useful gadget from a well-marketed one.

[Captains1911]

"Fit and finish" as its come to be related to an AR has nothing to do with accuracy, it's just a marketing gimmick that leads some people to believe they are getting a higher quality AR when they are not.

A better trigger may benefit a good shooter, but it won't help a bad shooter.

Ammo will certainly affect accuracy.

[timelinex]

Many people try to blame accuracy on so many parts, but in reality, unless your talking about bench rest accuracy , there are only few fundamentals.

The absolute most important thing is a good quality barrel. After that is the ammo you feed it. That's it. Everything else is over complicating the issue or masking marksmanship issues. A good trigger will quite often help the shooter achieve smaller groups, however that's because his trigger pull is bad. You can have a 10lb trigger and if your form is perfect, you won't shoot any less accurate then a 1lb trigger.

So slap a good barrel on your rifle, work up a good load or buy some match ammo and spend the rest of your time and money practicing your marksmanship.

[4V50 Gary]

As mentioned, the barrel is at the heart of accuracy. Get a bad barrel, and all the tricks to the gun or the ammunition won't make it shoot any better. Also check the crown.

Next thing is to handload the ammunition for the gun. Ammunition development can be tedious, but is absolutely necessary if you want the optimal performance out of the gun.

Good trigger is next and accompanied by good sights.

There are a myriad of other things that can be done. Free floated barrel, reducing any play between the upper and lower receiver, sling,

[Mobuck]

I'm not sure what you're expecting but I just turned a homebuilt carbine with a Delton M4(gery) flattop upper over to my older Son a few days ago. Scope sightin showed some pretty good sub 1" groups and a single 3 shot 300 meter group in a 10mph crosswind was under 3". That's pretty darned acceptable for a 16" carbine with a 1.5-5x compact scope.

[breakingcontact]

Not sure where you're at skills wise. I can't justify putting too much money into equipment until I put much more time into practice.

I'm decent, pretty good compared to most in the AR crowd that just blasts away, but until you've got the fundamentals mastered and the bad habits eradicated, don't focus too much on equipment.

[Edward429451]

I'm no long distance match shooter but adding a good RRA 2 stage match trigger to it did help me shoot better.

[chris in va]

A forum member managed to get a 3/4 moa group out of a stock Sport by handloading.

[Nathan]

Once you said 3 gun, the fog lifted. Get a quality 1-4x, dot or halo sight you like. Then practice. It really is more about you getting the gun to the same index point, learning rapid trigger press and transitioning from shot to shot quick. A match barrel won't help much, unless it is improving the balance of the rifle in hand.

[Edward429451]

Really. That's nice to know, having a BM standard model. I admit that I can not shoot up to my ammo (handloads) because I'm used to trying out my handloads with the scope on my flattop, and then putting the irons back on. I forget what my groups were @100. I know they weren't 3/4 MOA, lol. The best groups I've ever gotten with my standard model were with the scope and handloads which had IMR-4064 (hand weighed) in them, and some light weight bullets that someone had given me (hmm). Those I only shot at 50 yds and were ~1" so that would translate to 2 MOA @100 I think, which sounds about right. Usually if I can print 4" @100 I am happy with that because while it wont win any Matches, it will do everything else needed whether 4 legged or 2 legged.

Maybe I should try some of those 52 gr bullets that people speak so highly of in theirs (and mine) 1-9" barrels. I like heavy bullet for caliber bullets though, so haven't tried them. (handgun shooting did that to me, I think).

[MarkCO]

The only things that affect the inherrent accuracy of an AR-15 are the barrel, barrel extension to receiver fit and ammo. There are other aspects which help the shooter make the shot more repeatable and thus increase practical accuracy.

If you put the best barrel into a sloppy receiver and torque it up, it is likely you will end up with shot drifting due to heat. I've seen plenty of ARs rebarreled with heavy barrels that won't shoot much better because the barrel extension to receiver fit is sloppy.

The best barrel for 3Gun is probably the Nordic 18" AR Competition barrel. I provided design specs to Nordic last year and they took the chance on it and had a bunch made. I've had customers shoot 1/2 MOA with the first group and all of the ones we have built will go under 1 MOA with quality ammo. It is what I use and I have not used a better barrel. It is the hot ticket!

Two ways to ensure barrel to receiver fit is tight: 1. Buy the barrel and go to the LGS and try receivers until you get the tightest fit. 2. Buy the receiver and barrel from a shop who will check fit fo you. Yes, the barrel extension can be externally coated with rockset and then torqued, but then you have lost the ability to change barrels.

Free float tubes are almost a necessity for 3Gun since the positions are so varied and contact will occur. The long tubes are what most competitors use with the carbon fiber tubes having a very solid following to keep the weight balance proper.

Play between the upper and lower reciever does not affect accuracy, but there is not reason to accept it either.

The stock is a shooter repeatability issue and it has to do with proper fit and head alignment with a quality optic.

In 3Gun, ALL barrels get hot. The mid-weight 18" barrels are the better balance of weight and accuracy. Only the pencil weight barrels will distort enough to affect accuracy. Heavy barrels add weight and therefore minimize poor technique, but they don't hold groups any better from a solid bench than a medium wieght barrel.

The better the trigger, the sloppier your technique can be. A CMC trigger or a Rock River 2 stage is about as good as you can get on the inexpensive side. From there, you can get up to $300, but for very little additional benefit. Trigger feel is subjective and there is no one best.

Hornady Steel Match or Black Hills reman match is as good as you can get and not go broke for ammo.

The one thing you missed is a comp. Some will carbon up in the high presure port and degrade accuarcy, but most will help you stay on target for the all important 2nd shot. A Nordic Corvette or Miculek is all you need. The Miculek is a tad easier to install and set-up whereas the Nordic can be tuned a tad more precisely.

Hope this helped.