AR 15/10-M16-M4

[saltyphotog]

AR 15/AR10 M16 M4. what's the difference in these rifles. I am not speaking so much in calibers, but form and functions. Pardon my ignorance but I am a newbie. Thanks in advance.

 

[Mumbles_45]

The quick answer

AR-15 = 5.56

AR-10 = 7.62

M-16 = Military version of AR-15, several variations exist:
M-16A1 - thinner barrel, full auto, triangular hanguards, shorter stock, simpler/sturdier sights
M-16A2 - heavier barrel, 3 rd burst, round hanguards, longer stock, better sights
M-16A3 - Same as A2, but full auto and has removable carry handle
M-16A4 - Same as A3 but 3 rd burst and has a rail system instead of just plain plastic handguards.

M-4 = Carbine version of M-16. 3 rd burst, telescoping stock, Have a unique barrel profile to aid in mounting grenade launcher, and currently have a removable carry handle and a rail system.

 

[saltyphotog]

thanks

Now that's a concise answer! Thanks I appreciate it. You just settled a little argument... I won!

 

[Fosbery]

Also:

M4A1 - Carbine version of M16A3

 

[EvisceratorSrB]

The AR-10 is .308 right? I just don't want him to get mixed up with 7.62x51 and 7.62x39.

 

[Fosbery]

Yes the AR10 is 7.62mm NATO, not the Russian cartridgEs, although the SR-47 is chambered for 7.62x39mm (BUT if you have one of those, you'll be in US special forces).

 

[Mumbles_45]

Is the AR-10 .308? I guess the civilian ones would be, although the SR-25 and the like would be 7.62x51. I would imagine that the original AR-10 which preceded the AR-15 would have been chambered in 7.62x51.

 

[OrvilleYertleson]

It seems like there is some confusion here.

7.62x51mm is .308 NATO. They are the same round.

 

[Mumbles_45]

Not quite the same thing:
http://www3.sympatico.ca/shooters/7_62vs308.htm

and this difference is the one I'm wondering about. I'm pretty sure the original AR-10 was chambered in 7.62x51, but I would not be at all suprised if currently manufactured AR-10 variants meant for the civilian world have .308 engraved on the mag well.

 

[DougW]

M16A4 is the same as an A3 with a full auto position on the selector. (Son is an armorer in the Army, so it's his fault if I am wrong! )

 

[Mumbles_45]

'A3 has the full auto position, 'A4 does not. Don't know how to prove it to you, other than I've carried a couple 'A4s and I promise you the 3rd position on the selector was burst, not auto.

 

[TexasRifleman]

Not quite the same thing:

Well really they are. The thing is, the original specifications may differ a bit, but there are no current manufacturers making anything other than ammo that fits the .308 spec.

So you can win an argument on specifications, but not on reality.

 

[Mumbles_45]

I know, I fire 7.62 surplus and .308 whatever out of my rifles, but in the interest of nitpicking...

 

[LaEscopeta]

M-4 = Carbine version of M-16. 3 rd burst,...

Isn't the M-4 full auto? I thought it was supposed to fill the submachine roll of a personal defense weapon (PDW) with the ability to engage targets out to 100 meters. Also I think I read the M-4 trigger/cycling mechanism is significantly different from the standard M-16, to allow extended full-auto without jamming or wearing out the gun. I don’t know, I’m just asking.

 

[Mumbles_45]

I don't know anything about the trigger/cycling mechanism, but all of the M-4s I've been issued have been burst, not auto. Fosbury says the M-4A1 is the carbine version of the M-16A3, which presumably means its full auto. I've never seen one, but I'm sure he's right.

 

[MisterPX]

M4A1 is FA, and has a heavy barrel beneath the handguards.

As far as 308 being the same as 7.62. There is a difference, 308 has more oomph in it. Some manufacturers even recommend not using their 308 loads in semi rifles.

 

[Josh Aston]

Actually I'm pretty sure the M16A1 had round handguards. It also had teardrop forward assist and the birdcage flash hider. The original M16 had triangular handguards, three prong flash hider and no forward assist. The M16A2 went to the round forward assist button, brass deflector, different rear sight assmebly, four position front sight, and heavy barrel, as well as deleting the bottom ports of the flash hider. Since we don't use the A3 or A4 I'm not too sure about the differences there other than the flattop. Don't know about the Armies M4s but ours is flat top (not all M4s are) and 3rd burst. And we don't have an M4A1, the one we have now is the only one we've ever had.

 

[mp510]

Yes the AR10 is 7.62mm NATO, not the Russian cartridgEs, although the SR-47 is chambered for 7.62x39mm (BUT if you have one of those, you'll be in US special forces).

There are also some AR-15 varients in semi-auto only that fire the 7.62x39 round. Also, I do believe that there was a civilian version of an AR varient made that used AK mags, I could swear reading an article about it a couple years ago.

 

[OrvilleYertleson]

Every M4 I have used has been full auto rather than burst. I know there are some with burst, but I don't know which units actually use them.

 

[Mumbles_45]

Josh Aston, the A1 had the same triangular handguards, and 3 pronged flash hider (although I have seen a few with the birdcage) as the original M-16, the most notable difference between the two is the A1 has a forward assist, while the original did not. I forgot about the differences in forward assists and brass deflectors.

Since we don't use the A3 or A4

Nonsense. There are plenty of A4s in the Army and Marines and plenty of A3s in the Navy. I don't know what the Air Force is up to, some wierd GAU something or other with no forward assist.

OrvilleYertleson what unit are/were you in that gets issued full auto M-4s?

 

[MachIVshooter]

The AR-10 is .308 right?

Most of them, but they are aslo available in .243 Win. Armalite chambers the 10(T) in .300 Remington short mag, and Accuracy Systems, inc. will rebarrel a 10 to any cartridge that will fit the action.

I would not be at all suprised if currently manufactured AR-10 variants meant for the civilian world have .308 engraved on the mag well.

On the mag well of my Armalite:

RIFLE, 7.62MM AR10A2

I use commercial .308 Win., usually Federal American Eagle.

 

[Matt-man]

Bartocci's Black Rifle II states that the M16A3 is "...a standard M16A2 with the sole difference being that the BURST setting had been replaced by an AUTO setting." With respect to the A4, the book does not mention any other changes from the A2 configuration besides the flat-top upper and detachable carry handle (aside from the fact that USMC A4s are equipped with Knight's M5 RAS). The M16A4 rifle fire control settings remain SAFE, SEMI, and BURST.

On the topic of the M4, M4A1, flat tops, and full auto:

The upper receiver of the original XM4/M4 carbine was the fixed carrying handle type, fitted with the A2-style fully adjustable rear sight, the built-in fired case cartridge deflector, and round forward assist plunger assembly. Only the XM4 prototypes and one lot of M4 carbines were produced in the fixed carrying handle configuration. ... Colt introduced their new "flat-top" upper receiver in 1992, and early carbines shipped with the flat-top upper receiver were called the Colt M4A1 carbine, even though this nomenclature predated the US government's assignation of the M4A1 designation. In 1994, when Colt began shipping two types of M4 carbines to the US government, the designations were officially altered to reflect the fact that while both carbines were built on flat-top uppers, the M4 retained the BURST control, while the M4A1 utilized the AUTO fire mode.

 

[johnsonrlp]

All our M4s are burst, I've never seen an auto. BTW I had an M16A2 once that had the auto ground down and relabeled burst, and the 2 (of A2) looked like it had just been stamped on top of the 1. Anyway the funny part is it was FA not burst, I guess it never got converted.

 

[Josh Aston]

Mumbles, I meant the Air Force doesn't use the A3 or A4. And all of the A1s I've seen had the birdcage with ports all the way around. The GAU/GUU was replaced by the M4. There were several different models of the GAU/GUU, some had pencil barrels, some 203 profile barrels, some forward assist, some not, but all of them were full auto and none of them were flat tops.

 

[Fosbery]

M4 carbine is 3 round burst.

M4A1 is full auto.