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Thread: Reasonable accuracy expectation for 16" middy

  1. #1
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    Reasonable accuracy expectation for 16" middy

    I am looking at a couple 16" BCM middy uppers one BFH and one SS. My question is what is a reasonable expectation for these barrles? From what I have read here it sounds like the BFH barrle will have a longer "service life" but I will trade some life for some accuracy.
    I am not expecting a 1/2 MOA gun but is 1.5moa reasonable for a 16" middy?

    I assume this topic has had the dead horse treatmeant so any links to posts about the same would be great. The search function is not woking for me, I tried.

    Thanks

  2. #2
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    For a cl 16" middy from a reputable manufacturer, I'd be expecting about 2 MOA, give or take a half... Anything better than that is a plus. Both of my SR15's are almost 1.5 MOA, for example, but this was at 100 yards rested with a T1 and an ACOG 4x32, so it could be better if I had been using a 25x S&B and a machine rest.

    ETA - the above post is what I'd expect with 75 grain TAP or similar.
    Last edited by jonconsiglio; 06-02-11 at 15:55.

  3. #3
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    Using what ammo?
    My BCM 16" middie does about 2 MOA with Prvi 75gr, but about 3 to 4 MOA with XM193 or M855.
    Jack Leuba
    Director, Military and Government Sales
    Knight's Armament Company
    jleuba@knightarmco.com

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    I am thinking that if I can get 1.5 mao with ammo the rifle "likes" that would be ok, for matches or just messing around I am not that worried. The rifle will see way more time in the front seat of the truck on coyote patrol than at matches so with bullets more suited to that role like V-max or other "varmint" type rounds I was hoping to do better that 3 or 4 inches at 100. Thats more what I expect out of my mini 14.

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    I haven't had a chance to check my latest, but I will shortly. In any case the AR I put together a few months back with a Colt 6920 barrel and Troy Extreme Battle rail was shooting around 2 MOA if I remember correctly using Hornady 75gr. TAP ammo.

    That was with my ACOG in place IIRC.



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  6. #6
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    I'm no highpower shooter, and would be happy if I ranked at the less-than-mediocre skill level. My BCM Midlength is the standard gov't profile. With 55gr. PMC Bronze and Federal XM193 I can produce 1.5" - 2.0" three shot groups at 100 yards prone on a calm day. However, I no longer do three and five shot groups. All my groups these days are >= 10 shots. With 10 shot groups, most hover at around 3" - 4" at 100 yards.

    I have not run anything but XM193 and the PMC through my BCM midlength.

    Setup:

    BCM 16" midlength gov't profile
    Aimpoint T1 + ADM 1/3 mount
    Prone, mag resting on the deck with VTAC sling tightened up for stability
    Last edited by JimT; 06-02-11 at 13:35.

  7. #7
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    I asked this very same question several months ago on lightfighter and received some very good answers. 3-5 MOA for a non free float rack grade carbine seems to be the concensus.

    "I bought a new mid length AR carbine last month. It has a chrome lined 16 inch, 1/7 govt. profile barrel with standard non-free float handguards. I won't name the brand but it is one of the higher quality AR's that use milspec quality parts and inspection/test processes.


    With about 600 rounds fired I have yet to get what I consider to be consistent reasonable accuracy of 1.5-2 MOA. My very best 5 shot group has been just under 2 MOA at 100 yards. The worst 7 MOA. Most groups fall between 3-5 MOA. All firing has been performed at a range with concrete shooting benches using sandbagged rests and quality optics.

    I have fired a variety of different ammunition including Federal XM-193, American Eagle 223, Remington/UMC, Wolf and HSM 52 grain TNT.

    I have worked up many different handloads using Hornady 55 grn FMJ, 68 grn and 75 grn OTM as well as Sierra 69 grn SMK in a variety of configurations using Tac, AA2230, Varget, and IMR 4895 powders, CCI 400, CCI 450, and Federal 205 primers. I weigh each powder charge indivdually.

    The rifle performs best (about 2 to 2.5 MOA) using Hornady 55 grn FMJ handloads and worst (3-7MOA) using Hornady 75 grn OTM.

    For optics I started with a Leupold MK4 LR/T 3.5x10 epoxy bedded on DSA heavy 30mm rings.
    I switched to a Leupold MK4 MR/T 1.5x5 mounted in a ADM 30mm Recon-H cantilver mount with ring screws torqued per manufactures spec of 20 inch lbs.

    I lightly polished the standard AR fire control parts and installed JP 4 lb yellow springs and a Magpul MOE pistol grip.

    Nothing I have done has resulted in any significant improvement. I have a fairly solid base in regards to shooting fundamentals gained from the Marines and LEO firearms training. After shooting this rifle for the last month I am starting to question my own ability. After several frustrating hours at the range yesterday, another member let me fire his 20 inch free floated Bushmaster. I fired off 5 quick shots using my 55 grn FMJ reloads and all 5 shots fell into a 2 inch vertical line. I then removed the scope from my carbine and fired 5 quick shots using the BUIS and 55 grn reloads. All 5 went into a 1 inch circle at 50 yds. I have also performed dry fire drills using a laser boresighter and my trigger control appears sound.

    I am out of ideas. My optics, conditions, and components are excellent. I have lightly rested just the rear of the handguards on a single sandbag and locked the entire rifle up in several sandbags. It makes little to no difference. At this point Im thinking it's either me or the barrel or is 3-4 MOA all I should expect from a top quality carbine, scope, mount, and ammo package?


    Weaver

    Posted 30 December 2010 04:38
    1) That's pretty good accuracy for a 16" AR. That is quite good for a non-free-float barrel.
    2) That's quite good accuracy for some of the ammunition you mentioned. The factory loads are all stuff I would expect to turn in 4-6MOA at best - cannot speak to the quality of your handloads, but you may simply not have found what that gun likes.
    3) What do you expect? This ain't a match target gun - it's an AR carbine. You should be happy with anything in the 2-4 MOA range.



    Humminbird
    Long Time Posting Guy

    Posted 30 December 2010 04:46
    With the 55grn FMJ bulk ammo it's normal to get 3-5 MOA from prone unsupported, but with handloads you can reasonably expect around 2 MOA for groups with 10 or more shots.

    If you suspect problems, you could start by checking the barrel nut, I've seen some that were loose from the factory, although not on high quality ARs. Anything could happen, I guess. Visually check the barrel, all it takes is a bad crown and accuracy goes to hell.

    I would also try shooting groups with iron sights to see if there's a problem with how the optics mount fits your upper. It's unlikely, but I've witnessed issues with other quick detach mounts, so it's worth checking.

    You could always ask the manufacturer to take a look under warranty, if you think there is an issue.


    Pat _Rogers Premium Membership
    Leadership Moderator

    Posted 30 December 2010 04:53
    Good Morning!

    Are your expectations exceeding the reality of what a carbine is?
    4moa is the standard, and while some guns are capable of better accuracy, most shooters are not.

    I have nothing to offer you, as i don't shoot handloads, for a variety of reasons. But in the day when i shot High Power i did reload. I found no difference between loading my 308 match loads on a Dillon 550 than wasting time individually measuring powder loads.

    Would putting a FF handguard on the gun make it better? Maybe.

    But i don't bench rifles- unless there is an overiding reason to.

    But, if i was looking for 1.5moa accuracy, i would look at a dedicated SPR, and avoid anthing XM, wolf etc and stick with a viable brand of ammunition.

    And have a more realistic expectation about what a carbine is for.


    S/F

    Pat sends
    www.eagtactical.com

    GSeriesFAL
    FNG

    Posted 30 December 2010 07:44
    So you guys are telling me I am expecting too much from a standard AR carbine. It sounds like accuracy wise an AR with a 16 inch barrel is not any more accurate than an AK then.

    RTS
    FNG


    Posted 30 December 2010 07:55
    Your rifle does not sound like a target rifle so 2-4moa is fine and is about what could be expected. 2-4moa is more than enough to get the job done in that setup. The next time you ask advice about accuracy don't tell anyone you tried wolf to deterime what the accuracy was.


    strawman


    Posted 30 December 2010 08:04
    There are things you can do to improve accuracy, but don't expect your rifle to be something it is not. If you buy a carbine, expect reasonable combat accuracy. If you want to shoot little bitty groups, buy a gun that was built to do that.


    Pat _Rogers
    Leadership Moderator


    Now i know you have unrealistic expectations. Roll Eyes

    Some reality.

    The AK, Mini-14, M-14 and M1 all have similar accuracy standards- figure 6 moa.
    The AK is further complicated by the open sights and generally poor ammo.

    The M16- in all of it's configurations - is the most accurate Service Rifle that the US has ever fielded.

    If you want an AR type that is super accurate, don't get a service grade carbine with standard handguards.

    Look at getting a Larue gun- which will likely give you something you are looking for.


    S/F

    Pat sends
    www.eagtactical.com
    "

  8. #8
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    Quote Originally Posted by Failure2Stop View Post
    Using what ammo?
    My BCM 16" middie does about 2 MOA with Prvi 75gr, but about 3 to 4 MOA with XM193 or M855.
    That's pretty much what I meant in my post. I should have clarified that my SR15's only get that level of accuracy with 75 grain TAP and the 2 MOA I prefer from my rifles is also with that ammo, or other quality ammo.

    I don't expect that out of my training ammo.

  9. #9
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    ~3 MOA seems to be the standard with plinking ammo. I shot these off a bench with a BCM BFH 16" middy and Geissele SSA and Aimpoint M4 w/ 2 MOA dot all at 100 yards.

    PMC .223


    Federal XM193AF


    Prvi Partisan 75gr Match


    Fiocchi Match 77gr Sierra MatchKing

  10. #10
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    Quote Originally Posted by Nightvisionary View Post
    I asked this very same question several months ago on lightfighter and received some very good answers. 3-5 MOA for a non free float rack grade carbine seems to be the consensus.
    wow, if thats off a bench I'd really have to question the ammo or bullet weight/twist combination... that seems quite high.

    Even our cheapest doublestar 5.56 M4gery is shooting better than 3 MOA with PMC bronze... it's way more accurate then Mini's with the same ammo.

    I'd get some premium 5.56 match ammo and try the sandbags just to see what the upper limit of accuracy is.

    Personally, I don't believe that free float tube (or lack thereof) will improve that type of spread significantly for 16" barrels from sandbags. (CMP type shooting with huge sling pressure could make a difference, however)

    to put it in perspective, rack grade M4 clone Grendels with "gov profile" shaw barrels are seeing sub-moa on a regular basis without free float. My current 16" middy (LMT complete lower, M4gery config upper, M4 profile barrel minus the 203 cuts, MOE handguard) is consistently sub-moa on sand bags if I do my part.

    Not to advocate Grendel or bench shooting, just to point out that rack grade m4geries *can* shoot sub-moa even with non-free float 16" barrels in M4 profile.

    While I think I could pull a non-freefloat lightweight pencil barrel with a sling, possibly even an M4, the sling approach to do so would not be aligned with the typical tactical doctrine for carbines!

    But if you want to see what the weak link in the accuracy you have to hit the bench with known good ammo to determine the baseline accuracy. I'd start there before chasing accuracy improvements.

    The Grendel ammo (Hornady factory & handloads) probably would be considered premium match ammo, so I suspect that's much of the difference. The Grendel cartridge design is also very accurate, though I don't think 5.56 is at much disadvantage with premium loadings.

    Generally, Wolf PPU Grendel in rack grade setups (non-freefloat) is 1.5 MOA'ish in the MPT loading. And 2-3'ish in the soft point loading.

    So ammo can make a very large difference even in Grendel.

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