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What is the difference between A2, A3 and AR?

Discussion in 'Rifle Country' started by .cheese., Jun 20, 2007.

  1. .cheese.

    .cheese. Well-Known Member

    They look the same to me.

    I'm still learning about military style rifles. Thanks.
  2. 50 Shooter

    50 Shooter member

    You got different stuff like better sights, different hand guards, a shell deflector, improved flash hider, different barrel profile...
  3. Outlaws

    Outlaws Well-Known Member

    Well if I recall, for M16's A1 and A3 are select fire with automatic, fixed carry handle. A2 and A4 are select fire with burst, flattop uppers. AR is the civilian version of the M16. The different types of A1, A2, A3, and A4 are less of a actual model for the AR world and more just whatever the company wants to call it, but generally the A3 and A4 would be flattop uppers and the A1 and A2 are fixed carry handle. Someone will correct me if I got any of that wrong, plus I think there are a couple other differences.

    A stands for Alteration.
  4. .cheese.

    .cheese. Well-Known Member

    ahh... so they are the same, just with different modes of fire and slightly different default accessories?
  5. Langenator

    Langenator Well-Known Member

    M16A1-1/12" twist barrel, full auto, 5 clicks per rotation front sight post, slightly shorter buttstock, triangular handguards, fixed carryhandle/rear sights without BDC

    M16A2-1/7" barrel, 3 round burst, 4 clicks per rotation front sight post, longer buttstock, round handguards, fixed carryhandle/rear sight with 300-800m BDC

    M16A4-same as A2, but with rail system handguards and flattop upper with either removable carryhandle/rear sight or folding BUIS.

    I think the M16A3 is the same as the A4, except full auto instead of burst.

    As used in reference to civilian (semi auto only) ARs, the terms A1/A2/A4 refer to the other characteristics.
  6. funfaler

    funfaler Well-Known Member

    For the AR15, civilian rifles here is the basic differences

    The A2 has a fixed carry handle
    The A3 has a removable carry handle

    The rear sights are technically calibrated differently, but you won't know the difference, they are both adjusted, essentially, the same way, and they are both adjustable for windage and incorparate a BDC. The A1 does not have a BDC rear sight.

    All AR15s are semi-auto, unless modified. If it comes from the factory with auto-modes, it is an M16.

    Good luck
  7. Jeremy2171

    Jeremy2171 Well-Known Member

    M16A3 is the the same as an "A2" but it's Auto instead of "burst".

    Bushmaster IIRC coined the "A3" as thier semi-A4 style rifle.
  8. praharin

    praharin Well-Known Member

    i have held an m16a3, and it was burst. it had removable carry handle and round handguards. the m16a4, which i have fired had all that and a knights armament 2 piece non free floated rail handguard. though it wouldnt be dificult to make any of them with an auto marked reciever and the appropriate internals
  9. Jeremy2171

    Jeremy2171 Well-Known Member

    Don't know who's "A3" you held but it's not GI ....the M16 repair manual clearly states what is what...and A3 is an A2 but "auto".
  10. Ash

    Ash Well-Known Member

    In civilian AR rifles, the A1 refers to the original style rear sight, which is adjustable only for windage, coupled with the 5 click front sight, but with the deflector (and as such, is really more like the Canadian C7). The A2 refers to the updated rear sight which is fully adjustable (elevation and windage, as requested by the Marine Corps). The front sight is less adjustable, but this is because it doesn't need to be. The rear sight has a larger ring battle sight for close range and a smaller for longer range, but the elevation is the same (range is adjusted by a knob beneath the sight).

    A3 and A4 are interchangeable in civilian AR's, and refers to the flat-top receiver which may or may not also have a removable front sight (or no front sight at all).

  11. Jeremy2171

    Jeremy2171 Well-Known Member

    The front sight isn't really "less adjustable" The A1 front sight was round and was 1 click per 1" @100. However the roud sight causeg glare and was hard to get e good sight picture with. They went to a square front sight and the adjustments changed to 1 1/4" per click but a MUCH better sight picture. All my A1s now have "A2" sights in them.
  12. Ash

    Ash Well-Known Member

    Here's a graphic of the commerical rifle differences.

    Attached Files:

  13. praharin

    praharin Well-Known Member

    i held it in iraq. dont remember whos it was, but he was in the army. he was looking at my a2 with leupold mr/t. it had normal handguards, removable carry handle and was distinctly 3rb
  14. Outlaws

    Outlaws Well-Known Member

    Maybe it was an M4A3? The M4A3 is burst if I recall. Either way, M16A3's can't be the same as M16A2's because the A3 is a flattop. You can still get a carry handle, but they are on the rail.
  15. otomik

    otomik Well-Known Member

    M4 has the M16A2 trigger group (burst rather than auto)
    M4A1 has the M16A1 trigger group (auto)

    never heard of such a thing.
  16. Jeremy2171

    Jeremy2171 Well-Known Member

    Ummm the "A3" IS the same as an "A2" except the "A3" IS FULL AUTO.

    NO removable carry handle.

    The only two carbines in US service are the:
    M4 - burst and with or without detachable carry handle
    M4A1- As above but full auto and "heavy" barrel.

    Now the USAF is a whole different monkey....thier carbines are "generally" like the M4s but may have different sorts of barrel and such, some ARE M4s but others are old '64 vintage "M16" lowers with slickside uppers and an M4 barrel and handguards..to them its an M4. However the USAF has different designations like a GUU-5/P or GAU-5 depending upon which barrel is on it and what upper....to many variables to go into.
  17. Onmilo

    Onmilo Well-Known Member

    Colt product number R0770 M16A3 Carbine.
    14.5" heavy barrel, 5.56 caliber, 1-7 twist, chrome bore and chamber, relieved feed ramps, A2 muzzle compensator/flash eliminator, bayonet lug, Carbine handguards, relief cuts for M203 grenade launcher mounting on barrel,
    heavy buffer, flat top upper receiver, includes detachable carry handle unless otherwise specified, FULL AUTO selector switch, sliding buttstock assembly, standard pistol grip.

    These are the basis for the SOPMOD carbines in use with Special Operations Group.
    The heavier barrel prevents bursting when they cut loose on full auto, rock and roll, sustained suppressive fire with those nifty BETA-C magazines.

    There are three other Carbines of this type designated as M4 no 'A's that use the standard profile M4 barrel and the FIXED carry handle A2 upper receiver
    R0777 has an AUTO selector switch
    R0778 has a FOUR POSITION selector switch,(Safe, Semi, Burst, Auto) and special guts to make everything work right.
    R0779 has a BURST selector switch.

    Another Carbine, product number R0780 is designated as the M16A3 Command Carbine
    This is the old XM177 11.5" barrel with suppressor/flash hider, bayonet lug, A1E1 fixed carry handle A1 sight assembly Upper with cartridge deflector and round button forward assist, 1-7 twist, chrome lined bore and chamber, and BURST selector.

    Ain't figuring out what Colt is actually producing at any given time fun!

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