600 yard steel shooting with 5.56 - 9/2/2017 - Sub MOA @ 1000 (lol but for real)

General Firearms Precision Rifle - Semi-Auto
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[b]9/22/16 All of the pics are gone due to a photobucket problem a few weeks ago. But new pics are in post #209

I’d like to personally thank Noodles’ bundle of pessimism for giving me the motivation to make this possible.[/b]

Post #54 has my build progress so far. Much of this OP is irrelevant now but lots of good info from SMEs and pros in the responses.

I’ve got a lower begging for an SPR build. I would like to shoot 4" steel hangers at 600 yards with it. I previously had a Noveske upper in 300BLK that was a tack driver and great for hunting but that round will not reach 600 yards.

Questions:

What barrel length should I go for? This will be shot suppressed. I am fairly set on 18" as it will provide a boost in velocity without being too long, but I will consider 16" or 20" if someone can provide quantitative and qualitative reasons for doing so.

On that note, what upper should I buy? I’m really liking the BCM 18" with KMR-A 15" price point. It’s like $800 delivered with a rail panel for my Atlas.

What load (I reload) or factory ammo should I be shooting to do what I’m trying to do? I have no experience with precision 5.56mm.

My lower has a carbine RE. I’d prefer not to remove it and get an A5 but I will if necessary. Can a carbine RE work with an 18" barrel? What buffer would I need?

I have an 2-8x Vortex already mounted in a Bobro from a previous build. I’ve shot to 600 yards fairly well with a 4x ACOG but never at 4" hangers. I plan on upgrading the scope eventually as I know it isn’t ideal, but will the 8x be a waste of my time or can I get away with it for now? $1000 for an upper is a lot easier to swallow than $2500 for an optic and upper.

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The velocity difference between 16" and 18" is not THAT much… from my experience, it was <100fps with my 77gr handloads. I have 2 18" Rainier Ultramatch barrels (rifle & intermediate gas) and one Noveske Recce 16" barrel (mid-length) and they are all tack drivers. With that, I do like the 18" barrels more, but the 16" is more handy if walking around (i.e. hunting). If only target shooting, I would grab the 18" every time. Longer gas system/heavier = less recoil. Not that 223/5.56 has much recoil to begin with… but it should help you stay on target to see impact.

Run some ballistic calculators with 2,700fps for the 18" and 2,615 or so for the 16" and you should have a fairly good idea on the difference in drop with 77gr pills. The suppressor should boost the velocity a little also.

You don’t need the A5, but it sure is nice to have. I ran my 18" intermediate with a carbine RE for a while before upgrading all of mine to A5’s. I don’t remember what weight buffer I had, but it seemed to work well.

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Good advice. Although I prefer the 16". You won’t notice the effect of an extra 2", ever, but at least with the 16" you could reconfigure the upper to be used as a carbine pretty easily, and you will notice the 2" moving around and esp if you do anything in and out of vehicles.

I went 16" on mine and love it. It’s light enough that if I swap the scope for an aimpoint, I’m good to go on the same gun.

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I would roll with the 16" over the 18" gun. Like others have stated, you will not see much velocity difference between the two. I find the 16" to be handier as well. A 16" will get you to 600 yards no problem, I regularly shoot a 12" plate at 600 yards with a 13.7" Noveske.

My gun loves the factory Hornady .223 75gr Match loads. They also have a 0.39 ballistic coefficient which helps with wind at that range. In my experience it is a sub-MOA load. I’ve shot this load out to 750 yards.

I’d also use the Vortex 2-8 until you can afford something better. I’m sure it will be fine to use to evaluate accuracy and testing of various loads for your rifle.

Sent from my LG-H900 using Tapatalk

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The rounds will get to 600, no problem.

Hitting a 4-inch plate at 600 (asking the rifle to group better than 1-MOA) is a stretch. Maybe on a windless day, free-floated, with hand-loaded 73-77 (mag-length) or 80s (single-fed) and a good scope off front and rear sandbags.

Minute of Hajji (or E-type silhouette), sure. Better than 10/X-ring, don’t bet a pay check.

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True, With 77gr SMK/TMK, my gun does it all day… ME on the other hand…

Any decent mirage on a 4" steel plate at 600 will be the difference between a frustrating miss and a lucky hit. As it is with echos, I know the holds for my 11.5" out to 500y with an aimpoint, so yea, big difference there.

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I wouldn’t want to rain on anyone’s parade or be the cause of discouragement but I agree with sinister, 4" at 600 is a tough target.

Every 1 MPH of 90 degree wind will move your bullet about 4" at 600.

The difference in velocity between a 16 and and 18 inch barrel is going to be about 75 FPS. This may not seem like a lot but at 600, 75 FPS gives you around 9" less drop and 1" less windage per 5 MPH wind. Personally I like all the velocity I can get as I like to push my 18" SPR to 1000. :cool:

For bullets I like the Hornady 68 BTHP and the Nosler Custom Competition 77. That isn’t saying that the others aren’t as good, just that I can get those at a good price and they shoot great in my guns.

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I’m a pretty decent shooter and I’m pretty happy with 2- 4" groups at 200, with a rifle that will shoot sub MOA, consistently, at 100 yards.

My longest kill shots on deer with my Sako .308 bolt were at around 240 yards. I wasn’t super confident, given the variables, in a clean, humane kill at that distance. I got a bit lucky as they both dropped dead in their tracks with a couple of through lung shots.

Re-evaluate your expectations or you are setting yourself up for disappointment.

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I make sub MOA shots 600 yards consistently firing off a bipod with a rear bag out of my Krieger Barreled Rem700 in .308. There should be a pic/thread still up in the precision bolt gun forum of me doing so at 500.

I guess I need to back up a bit with my questioning: Is a 5.56mm AR platform capable of achieving sub MOA groups at 600 yards? If so, what uppers? Is a BCM SS 18" upper going to get me there? Do I need a 20" BCM SS? Noveske? Or should I be looking at 24" Kriegers? Assume the shooter variable is taken out of the equation.

I’m not trying to shoot competitively against .243s and 6.5s. Additionally, there are 6" and 10" steel hangers right next to the 4" so the worst case scenario is that I have to switch to bigger targets should the rifle not perform or the wind get bad, but that 4" bastard is my goal. :cool:

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Quality of the build in toto is gonna be a determining factor. A 16-inch can reach 600. A “Loose” barrel and Green Tip Ball ain’t going to cut sub-MOA.

Give it a whirl with what you got first before throwing money at a goal. I’d go for a fine trigger first (Geissele NM or tuned Milazzo-Krieger II); a quality float tube (whatever configuration you want your SPR-ish); best hand loads you can make; and a really good scope and mount.

A Krieger 700 in 308/7.62 is gonna have some advantage over a short, non-floated/non-enhanced gas gun.

If you’re going to build an 18-inch suppressed SPR don’t scrimp. Get John Holliger, Frank White, or some other guy who custom turns barrel blanks to build it right. I have no experience with BCM’s SPR uppers but have heard they use Criterion (button-rifled) barrels. “Better” maybe, but not “Best” quality.

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18" is fine, but you need a stainless match barrel. I second John Hollinger as a great source. I’ve built two 18" guns with his barrels. But, I shoot 8" at 400 and 12" at 600 because I like to hit it most of the time. 4" at 600 with 5.56 is just sick. If you can spot your misses, it might be a fun challenge. If you can’t spot them, it’s just frustrating.

Remember, putting 5 shots into a 4" circle at 600yd is very hard. Putting them all into THAT SPECIFIC 4" circle is damn near impossible. The F Class 600yd 10 ring is 6". And that’s bolt guns firing 6.5x284 and 6 Dasher and stuff. The 9 ring is 12", so if you can hit a 12" plate reliably, you could score real well in F-class.

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I’m running an 18" rifle length gas, suppressed set up with regular carbine spring and H3 buffer. I hit the desert last week and set up at 700 yards. I was getting hits 3 to 4 out of 5 times with 77gr tmk handloads. I did not bring a rear bag but wish I did. Only had a bipod and was laying prone on uneven terrain. The target was a 12" wide, 18" tall plate. The wind was constantly changing and we were shooting over a valley. I’m a novice at making wind calls. It was tons of fun! Hitting a 4" plate at 600 in perfect conditions sounds doable for hits every few rounds but not consistently.

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World of difference between 150+ gr 762 and ~77 gr 556 at distance.

Statistically, the 762 hit percentage, (180gr) with 5% wind uncertainty at 600 yards, on an IPSC target, can be as low as 70%. Contrast this with 300 WM (230gr) same set of assumptions, is 94%.

556 will be even lower. So, it all depends on how well you can read the wind.

How much lower will depend on bullet choice and MV, assuming you’ve accounted for the other variables.

Not questioning your ability or trying to talk you out of trying. I’d actually like to see video once you’re done.

I’d probably go for 20" to squeeze every last drop of MV as possible. I’m not a good enough wind reader to attempt it, but it would be fun to try.

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I would go 18". I’ve got an 18" rifle gassed barrel from AR15 performance. This video is at 500 yards, and was my first 3 shots using PPU 69gr BTHP Match. I didn’t get the video at 600 yards but it was the same. I was shooting off of a bipod out of the back of a truck.

//youtu.be/1Hxu8cYdkbg

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However you set it up, my best advice is take that 10" plate and paint it to blend with the background, then paint the center 4" a color you can see from 600. Honestly I think you’ll learn a whole lot more a whole lot faster and have a shload more fun if you can see where you’re missing and how you’re grouping. I shot a couple AR’s a fair amount this summer at 500 and hung a fresh backer behind my steel, figured it better to know, rather than wonder, where the misses were.

I was actually getting 60-pus% instant gratification with a 5.45 S&W with 4X Millett DMS-1-- 9X12 steel from Widener’s.

A 5.56 with a salvaged-from-KaBoom Lothar Walther nitrided barrel and various SMK factory loads, and a Millett DMS 2 (1-6X), well, no problem getting 100% hits or close to it.

Nice calm days they were, didn’t learn a thing about that which separates the men from the boys at distance :slight_smile:

Millett DMS-2 has aiming dots for 2, 3, 4, 500 yards. Even the 500 yd dot, for my combo and conditions, was right. Effing. On.

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Thanks for the replies everyone. Lots of good info and it appears I need to go dedicated long range if I want to make this a reality as a 16" bespoke upper probably won’t cut it.

Some thoughts so far:

Krieger makes a 20" blank and I could have the same smith who put my 308 together chamber it. I understand 5.56 has more limitations at distance than heavier 308s but aside from that is it a safe bet if Krieger can make a good 308 barrel their 223 AR barrel should be good too?

Does hand guard choice have any effect on accuracy? If I went 15" KMR-A vs 15" DD Lite III is there a preference? One is $200 more. But stiffness has to mean something I’m assuming…

Why are MURs out of stock everywhere?

As for the lower - I’ve already got an SSA-E and have ordered an A5. Is the SSA-E light enough or should I get something lighter? I love the SSA-E but it’s obviously no Timney 510.

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Kreiger is excellent. Does your smith do AR barrels? Installing an AR-15 barrel extension is not the same as chambering a Rem 700 bolt action - not harder, just different, and you don’t want someone to learn on your blank.

A few more notes about 600 yards, steel, 5.56, and AR-15s:

My 20" NM WOA build with 69gr SMKs drifts 2.6" in a 0.5mph wind out at 600yd. A breeze so light you literally can’t feel it will whip that bullet clean off a 5" target. A 2mph miss on wind call will have you 10.4" off. In other words, have a way to spot your misses and adjust, or you’ll never hit anything. I usually shoot a 24" square plate and then work my way to the bull. Remember also that 1/4 MOA clicks are 1.58" at 600yd, so just a single click will move you from the center of a 3" X ring, into the 10-ring.

All those numbers are basically 2x what you’ll see with a good .308 bullet.

When fired from a magazine, that carefully-seated bullet is getting rammed at an angle into the feed ramps, and being used as the lever to pry the rest of the round up out of the feed lips. The meplat take a whack during that process, and then the whole thing comes to rest with a little bit of play, since a semi chamber must have a little extra clearance to let rounds cycle cleanly. That violent process is really not conducive to getting the bullet started perfectly straight down the bore. So, you’re going to have trouble squeezing BR-type accuracy from a semi in any case.

All this is to say: be ready to shoot groups 2x the size of your .308 at distance, even with a great build. I’ve seen your .308 thread and those are killer groups; not readily duplicated by anyone with an AR.

SSA-E will be just fine. That’s my trigger of choice for an app like this. My guess is that you’ll find a lot more fun in whacking 6" plates at 300yd REALLY FAST than lobbing shots to 600 with this gun. I very rarely take any of my 5.56 guns to 600, because it’s just annoying compared to my .308. But the light recoil, fast bullets, and semi-auto action mean that from 200-400, I can settle on a target and whack it very quickly. The AR is far less sensitive to hold and pressure than a .308; even a heavy one. You can get your position all twisted up trying to swing from target to target quickly, and if the crosshairs are on the target when the trigger breaks; you’ll hit it. That’s the real magic of a setup like this. It’s far less forgiving at bucking the atmosphere at long range, but far more forgiving when rushing shots.

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Good point. I’m not sure he does AR barrels but it does appear that Krieger offers to chamber, headspace, thread and crown barrels themselves for not a significant price increase so that may be the route I go.

Thanks for the explanation about semi accuracy issues due to magazines as well. I always assumed bolt guns were inherently more accurate due to the fact you didn’t have any reciprocating mass and a gas system to deal with. That probably still has something to do with it but what you explained about the magazine and bullet deformation makes more sense.

At 600 yards the hangers are in front of a dirt berm and misses are easily observable on the 4" but group size isn’t measurable so the 10" with a 4" circle may be a better route.

This was the first time out with my Rem700 at 600yards shooting factory 168gr FGMM. My 175gr handloads shrink these groups to about 4" and I can ring that gong pretty consistently (hence the purpose of the thread :wink: ), but unfortunately I don’t have any pics of those groups.

What you can’t tell from the picture and why this is one of my favorite target pics is because this was my very first time shooting the rifle (I had just bracketed my groups to get it on target) I had gotten up off the gun to clean the barrel after every shot, it was on a Harris bipod, and the wind was gusting between 10-15mph (you can barely see a wind flag to the left of the scope in the first pic)

I enjoy the challenge of long range shooting. After learning how to do it, I found making wind calls and range estimations and really pushing the boundaries fun. One of the first rifles I ever spent significant time with shooting at a distance was a free floated 12.5" BCM SS barreled upper with an ACOG on it. The old BR guys at the range thought I was flipping nuts shooting M855 out of an SBR at 600 yards with a milspec trigger and 4x optic off a grip pod and wooden blocks :lol: 3 MOA 10 round groups were alright with me though…

I’m not sure why I share this other than to expand on where I’ve been and why I want this gun. You bring up an excellent point that the light recoil and semi auto nature are what I’m after with this rifle. The 700 is great for putting bullets where I want them to go, but the gun is heavy, it’s bolt action, and recoil is stiff even suppressed. I want something slightly lighter that I can transition to different targets rapidly.

I guess it becomes “Is the juice worth the squeeze?” If I can buy a bespoke $800 upper and ring the 10" all day and the 6" most of the time, but spending $2,000 and 2 months of lead time will only get me a 50% hit rate on the 4"…I’m not that patient nor rich.

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With sooooo many good barrels available that are AR-ready, I would go so far as to say it would be impossible to have one made up from a blank that would be any better. Kreigers=good stuff for sure (and available AR-ready) but I’ve been pleasantly surprised over the years what you can get out of what I thought were pedestrian barrels. Those heavy stainless varmint barrels on models available from several AR mfgrs are nearly all Wilsons (not Wilson Combat although they are now making their own). They are good groupers in my experience and a couple guys at Camp Perry told me they thought enough of them to have used them there in the past. I believe you can get these from WOA. My NRA High Master pal used a few on his way up.

My best grouper right now may not be the Sabre heavy stainless 24", it just might be the Voodoo 16". Not shilling for them but it’ll knock on half-MOA’ door with good 77’s and it’s a standard M4 profile.

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Thanks Ned. I was actually doing a bit of research from the posts here and all of the forum posts throughout the years on various forums kept resulting in me ending right back up at WOA and John Holliger. They seem to have quite a bit of selection.

I know what the difference is, but is there anything that should sway me toward .223 vs .223 wylde or 5.56mm chambers? Does barrel profile matter? I don’t want a 15lb gun, but I dont want stringing after 5 rounds as this is a semi auto after all.