View Full Version : 20" barrel, 1:7 twist, ACOG, Mk262.......is this an 800 meter setup?
Okay, maybe not with me shooting it, but is this setup capable of consistent 800 meter hits with some degree of lethality?
Ammo is actually IMI "Razor" stuff, but it is basically a Mk262 clone loaded to 5.56mm NATO pressures. The Sierra 77gr bullet has a good BC and the 20" barrel should wring the most velocity-wise from the load. ACOG is a TA31RCO-A4.
ColtSeavers
04-18-16, 14:43
My first concern is if the ACOG's 4x power will be too limiting.
My second is if that rifle can shoot well to begin with, also in conjunction with that ammo.
My last concern is terminal performance of the round itself at that distance.
None of this is meant as a snub against you, your shooting ability or rifle, just an order of concerns that i would try to address.
Fatorangecat
04-18-16, 14:55
I had an 18" AR with an ACOG and while the ACOG had really nice glass it was just not enough magnification for me. I ended up with a 2.5-10x optic. It suited the rifle well on both ends.
I am inclined to agree with Colt.
Using a 4x Mil-Dot Scope, I am speaking from personal experience, is hard enough at 2-5 hundred yards (let alone 100 yards just starting out), I couldn't even imagine myself trying to use the same mil-dot scope for 800 yards.
Granted, I know there is a huge difference between an ACOG and a couple hundred dollar scope, but when it comes to magnification, not to much difference will be there.
If the reticule is good enough, it certainly could ring steel; but in real-world application (military, etc), at that distance, the platform would be better off providing suppression of a "target" so someone else could move in closer or give a friendly sniper a long shot ability.
Is it possible? Sure. But I know I couldn't/wouldn't try. Haha.
But, I know I am not the most experienced, and I have been more than surprised after seeing some photos and footage of people hitting targets out to 1000 meters, but reliably and with fatality? I dunno. Not a good enough ballistician for that.
If you free-float it (DD Omega 12.0) and use a good trigger and 77s, 800 is on the far end of very do-able. Your limiting factor is the 77s.
You've got to be able to see the target with an ACOG or a 2-7 to 3-10 scope (nice, clear air; low mirage; good contrast against background).
This is 600 yards north of Phoenix:
https://www.ocabj.net/wordpress/wp-content/uploads/2014/02/Ocab-20140216-133753-1200.jpg
If you free-float it (DD Omega 12.0) and use a good trigger and 77s, 800 is on the far end of very do-able. Your limiting factor is the 77s.
You've got to be able to see the target with an ACOG or a 2-7 to 3-10 scope (nice, clear air; low mirage; good contrast against background).
Yeah, it's in a PRI carbon-fiber FF tube with a Geissele SD-C trigger in it. I know I am probably the biggest limiting factor but the comments regarding the 4x of the ACOG are well-taken.
Auto-X Fil
04-18-16, 15:22
Assuming you get 2818fps out of those 77gr pills, I calculate 1281fps at 800. That's still supersonic, and it drops 25MOA. That's workable but hard; about the same as shooting 1000yd with a good .308 bullet.
However, the ACOG is not going to be better than minute-of-barn-door way out there. Not only the 4x power, but the clunky drop reticle. Actually hitting a smallish target at 800 with that much drop and drift is going to require something with knobs you can spin.
I routinely nail a 24" steel plate with an iron-sighted 20" pumping out 69gr SMKs at 2750fps. I get much less drop and drift (15 MOA come-up), and note that I'm able to dial my shots with the knobs on my carry handle. It might actually be easier to hit a large (6MOA+) target at long range with irons than a drop reticle at 4x. If you happen to get your crosshair lining up with bullet drop on that day, then you'll bang the plate. If you are missing, trying to hold off will be futile. You'll have to spot your misses and then dial your zero at 800 with the adjustments on the ACOG - and if I remember right, there's no easy way to just crank back to a 100 or 200 zero after that.
Fatorangecat
04-18-16, 15:52
I can't remember who told me but when I was trying to accomplish the same thing with an ACOG I was given the following advice. Rather than sight in your ACOG at 100 yards and rely on the calibration of the drop in the reticle. Zero at 300 or one of the corresponding drop marks and work your way back. The idea was to shift the margin of error to the close end of the spectrum. I never got around to trying it but the concept seemed solid.
Auto-X Fil
04-18-16, 16:13
I use that method with any sort of pre-set calibration, dial or reticle. It works very well if the drop is somewhat close - assuming the ACOG reticle is calibrated for 55 or 62gr, I bet it'll be a sad match for 77gr, and the intermediate drops would be far off. But, that may be acceptable.
Edit: note that this works best when used on something like a hunting rifle. If you are dead-on at 300, but 2" off at 100 - no big deal. If competing or training at the range, typically you expect to be able to hit targets of similar angular size, not absolute size, at all distances. Going from 4MOA at 100yd to 1.5MOA at 300yd is great for a hunting gun, but lame otherwise.
jackblack73
04-18-16, 17:57
I have no experience shooting at that distance, but it seems to me that you wouldn't be able to see your misses. Thus, you wouldn't be able to make corrections. Assuming you're not shooting with a spotter
I had that same setup for my DMR in 2005. Douglas barrel, Daniel Defense rail, M262, Ta31 ACOG, and a KAC trigger.
I shot it in training out to that range and beyond. Mostly on junked cars. The rifle and ammo was definitely accurate enough for that task but the ACOG made it difficult for first round hits on man sized target at that range. However you wouldn't want to stand around and let me adjust.
I think doing it again would be fun and challenging.
If you really want to hit the target at 800 yards you will need more than a 4x power, or you are going to get mighty frustrated.
Frankly if you have any desire to do more than play around, I'd suggest going to .308 Winchester if you want actually to score effective hits at 800 yards.
Read this article for a dose of reality about shooting 5.56 out to 800 yards:
http://rifleshooter.com/2014/04/223-remington5-56-nato-velocity-versus-barrel-length-a-man-his-chop-box-and-his-friends-rifle/#prettyPhoto/12/
If you really want to hit the target at 800 yards you will need more than a 4x power, or you are going to get mighty frustrated.
Frankly if you have any desire to do more than play around, I'd suggest going to .308 Winchester if you want actually to score effective hits at 800 yards.
Read this article for a dose of reality about shooting 5.56 out to 800 yards:
http://rifleshooter.com/2014/04/223-remington5-56-nato-velocity-versus-barrel-length-a-man-his-chop-box-and-his-friends-rifle/#prettyPhoto/12/
Oh I'm under no illusions about 7.62 vs 5.56mm at distance. I was just thinking of it in terms like this: if I could grab only 2 long guns if things went "south" this would be one, as I would consider it my "distance" weapon (that term being rather loose) but was thinking 800 max. Not a constantly engaged-at distance but top end. It has an A1-profile barrel but is chrome lined and 1:7 twist (got it from McKay Enterprises a couple years ago when they had what were purported to be IDF contract overruns).
My first choice is my shorter, lighter BCM upper 14.5" middy with ELW barrel and T-1 RDS.
Only two?
A high quality semi-auto 7.62 rifle to drop them out to 800 yards and when they get to 100 yards, you can grab your BCM and have at 'em as they approach to within 20 yards, then you can shoot them with your handgun, they knife them, then jump on with your bare hands and choke them to death.
:)
basic hits on targets with a 4x acog? sure
these days i make hits on 14x16 plates out to 800 yds with a 1-7" DD M4V11LW with TA01 and cheapie FedAE55grFMJ. going to high-quality high-magnification scopes has allowed me to see better and tighten groups a bit, but i keep returning to the simplicity and speed of the acog (i've owned a number of acogs in the last 35 years, and have done lots of long range shooting with them, making pretty consistent hits even with 1-12" barrels).
i will add that my 55-grainers do appear to go subsonic somewhere after 900-yds, so 800-meters is getting out towards my limit (i've yet to have a satisifying day out at 1000yds). i can't speak for heavier bullets...
.
Eurodriver
04-19-16, 09:52
About 5 years ago I had a BCM 12.5" with Hornady Superformance and an ACOG.
Milspec trigger off a shit bipod with a rear bag got me this.
http://i1328.photobucket.com/albums/w521/6234987u02/102_0178_zpsggleoqiv.jpg
Target is at 565 yards
http://i1328.photobucket.com/albums/w521/6234987u02/102_0177_zpsjvykt5qy.jpg
http://i1328.photobucket.com/albums/w521/6234987u02/12.5_zpsi2ikdedi.jpg
I am now shooting a 20" Krieger with a 14x Nightforce from 600-1000 yards for obvious reasons. (https://www.m4carbine.net/showthread.php?179387-600-yard-steel-shooting-with-5-56-Post-161-First-Range-Report/page5)
I'm a huge fan of pushing the AR platform as far as it can go, but 800 yards with a fixed 4x and no windage hash marks is going to be a struggle at best. With that said, with a 20" barrel, good ammo, and a better trigger I think you could get minute of man if the wind isn't kicking around.
Okay, maybe not with me shooting it, but is this setup capable of consistent 800 meter hits with some degree of lethality?
Ammo is actually IMI "Razor" stuff, but it is basically a Mk262 clone loaded to 5.56mm NATO pressures. The Sierra 77gr bullet has a good BC and the 20" barrel should wring the most velocity-wise from the load. ACOG is a TA31RCO-A4.
On a windy day, you'll be very lucky to land hits at 4-500m with an ACOG without walking your impacts in... if you can even see your impacts or have a spotter that can see your trace. And even then, a change in wind is going to give you a bad time.
At 800m... yeah, no.
You can provide more or less accurate suppressing fire at 800m with your setup, but consistent hits in real world conditions? Unlikely. With lethality? Well, Mk262 out of a 20" barrel is roughly at 9mm muzzle energy at 550m or so, and you're still above .380 ACP at 800m. You should also still be supersonic, but just barely. Meaning you're basically at 22LR velocity with a heavier bullet at 800m. Plenty of people die from .22 every year.
On a windy day, you'll be very lucky to land hits at 4-500m with an ACOG without walking your impacts in... if you can even see your impacts or have a spotter that can see your trace. And even then, a change in wind is going to give you a bad time....
i concur with Koshinn about wind: its the biggest problem i run into.
using the set-up i mentioned above, i can often make first-round hits on the plate at 600-yd and even 700 if wind is dead calm.
but cross winds, on one of my ranges shown below, play evil tricks, so its iffy making first-rd strikes at 400 and further on a gusty day.
seven target stands from 100 to 700-yds:
http://i47.photobucket.com/albums/f173/oregoncoyote/Rifle-Range.jpg
My kid shoots a 16-inch middy with a TA01 and 77s to 750 against E-types and isn't even working hard.
My buddy Stephen is pissed-off with himself because 75s and 77s run out of steam (for him) around 875 with an 18-inch barrel and a 3-9 scope (against E-types) at 4500 feet MSL.
It's a rifle -- it ain't rocket science. Go out and shoot and see for yourself.
My kid shoots a 16-inch middy with a TA01 and 77s to 750 against E-types and isn't even working hard.
My buddy Stephen is pissed-off with himself because 75s and 77s run out of steam (for him) around 875 with an 18-inch barrel and a 3-9 scope (against E-types) at 4500 feet MSL.
It's a rifle -- it ain't rocket science. Go out and shoot and see for yourself.
LOL! The 800 range ain't happenin' 'round these here parts! Maybe someone with a farm or such but there isn't a public range near here out that far. I have a 100yd range on my property but that isn't even warming up for what I'm talking about. I believe Ft. Campbell has iron maidens out to 800 on it's POW range but I don't have access to it (not even sure about being a guest either).
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