Realistic accuracy expectations on the AR-15 platform


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dboyles
September 5, 2010, 07:16 PM
I don't shoot competitively, but I do like to challenge myself to get the most out of my rifle and ammo. On a good day, from the bench with a scoped (10x) AR-15 shooting .223, my five-shot groups will average a little under 1" at 100 yards. I don't fancy myself an expert rifleman or reloader, but this seems a little mediocre.

The problem I have is that I don't have any benchmark. High-power shooters are shooting irons at longer distances, and benchrest shooters aren't shooting AR-15s. If I've overlooked something, forgive me, as I'm not familiar with the world of competitive shooting.

What I'm really looking for is some hard numbers against which I can compare myself. What can a scoped high power-type AR-15 do from the bench at 100 or 200 yards? I'm talking about more than just the occasional great group. I don't even know that "group size" (in terms of extreme spread) is a good way to measure it.

Thoughts?

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jerkface11
September 5, 2010, 07:38 PM
Sub MOA 5 shot groups are mediocre?

Jim Watson
September 5, 2010, 07:45 PM
My AR is sub half-MOA but it has had a LOT of work done to it.

MOA for a quasi-military rifle is great.

Canuck-IL
September 5, 2010, 07:57 PM
Not enough details to really comment ... for one thing, the quality of the ammo can make a 1 MOA difference. With quality loads (handloads, Fed Gold Medal, Black Hills), I expect my 2 HP rifles to do 1/2 MOA at 100 yds - that's with a scope and a bench.
/Bryan

dboyles
September 5, 2010, 08:10 PM
Sorry, I was trying to fire off a coherent post quickly and get up to paint the trim that the wife has been bugging me about.

I'm looking for accuracy based on high-end components. Specifically, I'm using a LaRue upper with a stainless 1:8 barrel, new Lapua brass, Varget/H335, and SMKs. I use Redding Competition dies (full-length bushing sizing dies and a micrometer seating die).

The occasional sub-1/2" group isn't out of the ordinary, but neither is the occasional 2" group. I may be a victim of reading too many internet commando posts where their off-the-shelf Bushmaster will shoot sub-MOA "all day long" with factory ammo and an EOTech, but I look at my targets (even those that have five groups of five that average sub-MOA) and think "meh, could be better."

Of course, this leads me to want to keep searching for the perfect load, and to try every combination of components to get it. I'm trying to figure out where to draw the line, be happy, and just shoot.

For example, Jim, when you say sub-half MOA, what do you mean? That it can do that when the stars align? It'll average that on any given day? Are we talking 5-shot groups? That's what led me to wonder if there are any competition results to see what happens when we get down to brass tacks. Not to say that I doubt you, but I'm trying to balance my expectations with realism.

Thanks for the feedback thus far.

918v
September 5, 2010, 08:22 PM
It depends on the quality of the barrel, trigger, scope, and you. You are not going to see consistent .5 MOA with a 5.56 NATO chamber no matter how good your components. A Wylde chamber will shoot .5 MOA. A match 223 chamber will theoretically shoot the best, but it won't be very reliable. Les Baer guarrantees .5 MOA with his 223 barrels.

NuJudge
September 5, 2010, 08:39 PM
There's nothing wrong with the groups you are getting. Most Service Rifles probably can't do better than that. I can't remember the last time I scoped any of my .223's or shot them from a bench. I shoot them prone to test rifles & loads, in a sling, using iron sights, and a good group is about 2" at 200 yards. The 100 yard SR-1 reduced size bullseye has a 1.35" X ring. and the X ring at 600 yards is 6 inches.

Regarding ammo, if all you are shooting is 100 yards, load 52gr match bullets in LC or WRA brass with 26.5gr 748 and a CCI primer.

CDD

bogus mcall
September 6, 2010, 09:31 AM
My Bushmaster WILL shoot. 1/2 moa all day with black hills or my reloads. But it has a factory free floated barrel, jard trigger and burris 4.5x14 scope. It would probably do better but 1/2 moa is about all I can do.

SlamFire1
September 6, 2010, 11:29 AM
Sub MOA groups are very good, but I assume you are shooting off sand bag rests.

Now, get off the bench and learn how to shoot.

Rokman
September 6, 2010, 11:34 AM
Since you have high-end stuff, I doubt that you have much slop between your upper and lower. Cleaning that up on a couple of my builds made a difference for me. It appears that you have quality components to make good ammo. Maybe you can tweak you loads with different variables.

Zak Smith
September 6, 2010, 01:25 PM
The average AR-15 should be able to shoot "about" MOA with some ammunition.

A better AR-15 should be able to shoot "about MOA" with most ammunition.

A higher end AR-15 in good condition with the right ammo can often shoot in the 1/3-3/4 MOA range.

Any 3Gun match can be won with a 1 MOA rifle.

The X-ring for Service Rifle is 10 inches at 1000 yards, or just under 1 MOA.

dboyles
September 6, 2010, 03:31 PM
At the risk of broadcasting my mediocrity, here's a target that I went out and shot this morning at 100 yards. I hadn't tried H335 and SMK 52s together before, but thought I'd give it a shot and this seemed like a decent starting place.

SMK 52gr - 25.0gr H335 - Lapua once-fired (by me) brass - CCI 400 primer

http://picklematrix.org/guns/averagetarget.jpg

Group measurements (center-to-center) follow. Groups are listed in the order I shot them: center, then top left, top right, bottom left, bottom right. All were single-loaded except the bottom right (neck tension is probably too light). The wayward shot on the top right target truly was a called flier; the rest were okay to me as the shot broke. Conditions were good (85 degrees, 3-4 mph quartering wind).

1.18"
0.97"
1.28" (the four shot group minus the flier is 0.55")
0.82"
1.75"

All shots were slow-fired from the bench (sandbags). No cleaning between these groups. Gun is a LaRue Stealth 16" with a Nightforce 2.5-10x24 and a Geissele SSA trigger.

kutter
September 6, 2010, 04:06 PM
Personally I think with a 1:8 barrel that 52gr bullets are to light to get consistent results. I would start with at least a 62gr and work my way up from there. My Sig is 1:7 and it is really only happy in the 65gr and up range and it shines with 68 and 75gr Hornady.

taliv
September 6, 2010, 04:25 PM
I'd try a heavier match bullet.

Also I'd try a different target. Get a benchrest style target or a black bullseye and dial your nf up about 3 minutes so your bullet holes don't disturb your sight picture. I use that redfield target a lot and consistently shoot larger groups on it than other targets. The bright white background also causes my eyes to fatigue really fast so I can't focus after a few groups.

taliv
September 6, 2010, 04:28 PM
Nice rifle and setup btw

dboyles
September 6, 2010, 05:13 PM
I've actually got a lot more rounds down range with the heavy stuff than the light 52gr SMKs. I've shot plenty of 69 and 77 SMKs, and many 75gr Hornadys.

It's all part of the learning process (I've only been loading since January of this year), but I was under the impression that the lighter bullets will shoot a little better at 100 yards. If that's the case (and it's hard to tell without taking a more scientific approach), the difference isn't too drastic for me. I have considered standardizing on the 69gr SMK with Varget as a good balance between cost and versatility.

edit: Good point on the white of the target being fatiguing. I experience that too. I do like the diamond pattern, but I should probably play around with different targets in the name of consistency throughout a shooting session, if nothing else.

rhubarb
September 6, 2010, 06:34 PM
The Trouble With 3-Shot Groups (http://www.ar15.com/forums/topic.html?b=3&f=118&t=279218&page=1)

Stack the five targets on top of each other. You'll have a 25 shot group that tells you what your gun will do day in and day out. That is your realistic accuracy expectation.

If you shoot enough five shot groups, you are bound to shoot some that are under an inch. Trying to work up an accurate load with lead boolits in an AR, I shot hundreds of rounds in dozens of different combinations. One five round group was just over half an inch. I could claim to have a HALF-MOA RIFLE with that load if I didn't relate the fact that the next five shot group was a little over two inches.

MOA is only common and mediocre on teh intarwebs. My two High Power ARs will shoot around an inch at 100yds with my standard load. That's the same load for both rifles; not the best load for either, but a pretty good load. I honestly don't worry about MOA. You aren't scored in High Power for group size.

dboyles
September 6, 2010, 07:44 PM
rhubarb, the sentiment that you expressed is really the impetus for this thread. I've shot 5-shot groups that could be covered entirely by a dime, but that was a combination of a good load, good shooting, and good luck. With so many variables it's tough to make sense of it all. I'm just looking for a bit of a reality check.

I also agree with you on the importance of accuracy versus precision. I've given serious thought to changing my approach from shooting 5-shot groups and measuring extreme spread to shooting 1-shot groups and measuring distance from POA to POI.

taliv
September 6, 2010, 07:50 PM
the snipershide forum has an interesting policy on posting pics of targets. i think it's a bit extreme (especially since as a mod i don't want to have to go around deleting 90% of the targets posted here...) but they do have a point.

I'm a big fan of 5 shot groups at a minimum, but 3 shot groups have their place. Heck, my gunsmith (a benchrester) just does 3 shots working up loads, and Zak posts targets with 3 shot groups. I personally shoot 4 shot groups most often, but that's because i usually go to the range with 5 rounds and while shooting, see a bug i want to splatter, so i wind up with 4 shots.

Rokman
September 7, 2010, 12:04 AM
I can usually count on one round really screwing up a great five round group.

TonyAngel
September 7, 2010, 01:28 AM
I've been "precision" shooting for about three months now. I didn't build the rifle to shoot benchrest, but as more of a "field" rig, so I didn't go with a super light trigger. I'm running a Geissele SSA-E.

All of these groups were shot at 100 yards using this little 16" build...
http://i154.photobucket.com/albums/s265/ajangelettejr/DSC_0007.jpg

Three shot groups....
http://i154.photobucket.com/albums/s265/ajangelettejr/Groups/DSC_0006.jpg

Five shot groups...
http://i154.photobucket.com/albums/s265/ajangelettejr/Groups/DSC_0104.jpg

Ten shot groups...
http://i154.photobucket.com/albums/s265/ajangelettejr/Groups/DSC_0003.jpg

Twenty shot groups...
http://i154.photobucket.com/albums/s265/ajangelettejr/Groups/DSC_0005.jpg
http://i154.photobucket.com/albums/s265/ajangelettejr/Groups/DSC_0004.jpg

Of course, I'm still working on my skills. You can look at the groups and tell that the rifle is more consistent than the shooter. ARs certainly are capable of some good accuracy.

I'm still developing loads, and my loads are going to follow, so the obligatory...I do not guarantee that these loads are safe for use in your rifle. Always work up to any load to make sure they are safe for you and your rig.

I'm shooting basically two loads. 69gr SMKs over 25.3gr of Varget using Lake City brass and Remington 7.5 primers. My other load is 77gr SMKs over 24gr of Reloader 15, same brass and primers.

What has amazed me is the consistency. I'm running a 1:8 twist barrel with a 5.56 chamber and ALL of these groups were shot with a hot barrel. I don't play the shoot and let it cool game. My barrel cools while I'm loading mags and while the range is cold. The guys that I shoot with are always telling me to shoot five and take a break. I can't stand the sitting around. The rig might actually shoot better if I tried letting it cool for five minutes between groups. In all fairness though, I've gotta say that I do take a couple of minutes between groups. My eyes get tired and it's been HOT down here the last few months. Sweat dripping in your eyes is not conducive to accuracy.

My rifle does seem to shoot better at 100 yards with the 69gr bullets. I'm going to try some 52gr bullets and see how they do.

center shot
September 7, 2010, 11:04 AM
http://i47.photobucket.com/albums/f167/lh7588/DSC01111.jpg
20" Rock 1/9 twist, NM Float tube, NM trigger, cheap scope (Tasco)I use for testing loads.

TonyAngel
September 7, 2010, 01:51 PM
Not to get off topic, but is that load very temp sensitive?

MEHavey
September 7, 2010, 03:08 PM
These are representative of what can be done w/ decent aftermarket barrel/chamber/floated handguard


Effects of stand-off distance on particular bullet shapes. Note that this combination using the 52gr SMK likes to be sitting into the lands slightly. (never be "close to..." always be in the lands or off the lands.)
http://i25.tinypic.com/2hgzntg.jpg



Effects of combination of powder/bullet/standoff: Note that this 77gr SMK bullet is a good 0.020" (twenty thousandth's) off the lands when loaded to maximum magazine length:
http://i45.tinypic.com/10h0fvo.jpg

What this says is that there is no magic one-size-fits all combination; that yours will be different; and that (in my opinion) if/when you get reliable 1/2" center-to-center grouping... you're there.

TonyAngel
September 7, 2010, 03:51 PM
I hate to keep butting in, but does the above mean that when loading the 52gr SMK to mag length, that it will be in the lands? I'm asking because I'm new to loading rifle and have been sticking to loading my 69 and 77gr loads to mag length. It was my intention to do the same with the lighter bullets, although loading data suggests a 2.235 OAL for this bullet.

Zak Smith
September 7, 2010, 03:56 PM
I strongly recommend against loading into the lands, or particularly close to them, in a semi-auto. (I recommend against this for bolt guns too, but that's another topic.) From time to time this can cause a bullet to get stuck when you try to eject a live round and it's a mess.

center shot
September 7, 2010, 05:30 PM
In my rifles 52gr MKs are not in the lands when loaded to fit the mags. I use this load for 200 yard awful hand. I load a 68r. to fit the mags. for 300 yard rapid fire, and 77 gr. MKs loaded to the lands minus .010" for 600 yard prone which are loaded single shot.

MEHavey
September 7, 2010, 06:14 PM
I hate to keep butting in, but does the above mean that when loading the 52gr SMK to mag length, that it will be in the lands?

Not necessarily. It depends entirely upon how the throat is reamed. In my particular case the throat engages the 52gr SMK by at least 15 thousandths (0.015") when loaded to magazine length/2.26". I discovered that when I finally got the modified case for my Hornady/Stoney-Point gauge.

http://www.midwayusa.com/viewproduct/?productnumber=570611

And I also discovered that my 77gr SMK was off the lands even more than that when loaded to mag length. It all depends on bullet shape, not overall length.

OAL can only be determined (with any accuracy) for a cartridge/bullet combination using an OAL gauge like Hornady's, the exact bullet, and a Comparator insert that goes in the measuring/digital caliper.

http://www.midwayusa.com/viewproduct/?productnumber=231904

As you see, one size does NOT fit all, and there's no end to the games you can play


As to "engaging the lands" I suggest no one try this who has not very precisely run the bullet-by-bullet measurements as noted above -- and who uses a Comparator to detemine seating depth, not simple calipers and overall length. Bullets vary one to the other too much.

As before, be either in, or out of the lands -- not "close." I've chosen 0.005" into them to ensure the bullet and lands are just 'talking' to each other, not engaged in illicit coupling. :o

TonyAngel
September 7, 2010, 09:17 PM
I have no desire to load into the lands. I'm using SMKs because I read that they don't mind, and in some cases prefer, making the jump to the lands. At this point, I'm taking baby steps. I'm using a Lee crimp die for consistent pressure. Maybe it's working, maybe it isn't. All I know is that I wasn't shooting the groups I am now three months ago.

My barrel has a 5.56 NATO Match chamber, whatever that means. Well my 52s come in, I'll just have to load up a few dummies and see if I'm getting close to the lands or not. Then again, maybe I should just stick to what I know and concentrate on my skills for now.

Canuck-IL
September 8, 2010, 12:12 AM
"5.56 NATO Match chamber" - interesting combination ...sounds like a contradiction to me, marketing at play. I believe a standard NATO chamber has a longer, flatter leade as compared to a .223 or a Wylde - not likely you could keep a 52gr in the case and touch the lands in a NATO, let alone at mag length.

My WOA upper has a Wylde chamber (and they can differ somewhat among brands). The lands engaged an 80 SMK at 2.475 when new - way beyond mag length.
/B

TonyAngel
September 8, 2010, 12:55 AM
Yeah, that 5.56 NATO Match Chamber sounds like Voodoo, but the barrel shoots. I got it from Bravo Company. I did do some research and it's supposed to be some form of actual match chamber for 5.56 pressure rounds. I really don't know much about it except that I trust the vendor and my results have at least rivaled those of others with name brand barrels. It can certainly do better than I can.

Thanks for all of the info and sorry for steering this thread off course.

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