How are A2's better?

Hey everyone. I have been lurking on this thread for a while now, as I plan to get an A2 asap (meaning when I get an engineering co op lol). I just love the classic look and no-nonsense iron sights and stock. My question is, how are the A2's more reliable than other AR's of the same operating design? Are they really at all? Recent threads have made me curious of this. I am a little shady on my knowledge of how the gas system works, but I seem to understand the regular system does not use a piston. I am an AK guy so I am used to the piston. Are they better because the gas system is longer because of a 20" barrel?

I really want to get the best running rifle possible, because I really want another SHTF rifle that will run shitty (steel cased) ammo. Because of my needs/wants, I was thinking of getting a factory assembled Colt, just to eliminate the possible problems that seem to surface sometimes with built guns. I am not saying built guns are bad AT ALL. I really just don't have the desire to partake in all that.

Let me know if this is the wrong place for this please. Thanks!

The longer gas tube decreases the severity of wear on the moving parts of the gun.

Also, I think part of the reliability mantra comes from the simplicity of no optics, no rails, no bullshit.

Just a simple, functional, rugged rifle.


edited for goofiness

This. Remember that the steel cased .223/5.56 ammo from Wolf, etc. Is the Russians revenge for us winning the Cold War...

The gas port is farther away from the chamber than carbine or mid-length gas systems. This means the port pressure and subsequent operating pressure is lower than the other gas systems. The lower pressure, and longer duration of the gas traveling from port to gas key, allows the fired case to contract slightly after full obteration, by the time extraction begins thereby facilitating extraction. The longer gas system is also cleaner, cooler, and provides less wear and tear on components... in addition to a softer recoil impulse. Moreover, the rifle weight buffer and rifle length buffer springs also contribute to the reliability. The increased buffer weight when compared to a carbine weight buffer, slows the action down, again, facilitating extraction. Additionally, the heavier rifle buffer also has more momentum when moving forward which facilitates feeding.

I know it's not great for it, but I want something that WILL run it if that's all it gets fed. If I buy an AR that can't, I'll sell and get an(nother) AK.


Thanks for all the responses guys. It makes sense and is pretty damn cool

Arguably the 14.5" M4A1 Carbine is the most extensively tested and solidly proven and performing AR15 based, M16FOW system in existence.

Lower failure rates in rifle length systems could be attributed to lower use rates - M16s are by and large issued to support troops and lower ranking conventional troops (USMC), while SOF, who both train and fight more heavily and abusively [to the weapon] almost exclusively use carbine based systems.

The first generation carbines were less reliable than rifle length systems for some of the reasons mentioned, however, for all intents and purposes, the functional development of the M16 series ended with the M16A1, the only things that have been changed are barrel profile and furniture - insofar as the operating mechanism, no major changes or adjustments have been made to the operation of the M16 rifle since then.

On the other hand, the carbine length systems have continued to be tweaked and modified for maximum reliability.

While the benefits of rifle or midlength systems might be argued from a theoretical standpoint, and very may well be true - from the persepective of actual, real world, no shit, rounds down range, large sample size, combat efficacy, there is no more tested, vetted, or proven 5.56MM weapon system than the current issue M4A1 Carbine.

~Augee

The m16 has proven more reliable than the m4 in scientific studies done by the military. I don't care enough to look it up, but I think it was the Marines who did the famous "sand test" that has been posted numerous times on this board.

There's the "Pop Culture review" as well, when was the last time you saw people talking about the M-16A2/4's not working in Iraq and Afghanistan?

There was a Marine Corps test that did so claim.

There was also a subsequent Army test that directly disagreed.

Neither of these was the "Sand Test."

I guess it gets down to whose testing you believe more, Army or Marine Corps?

Both tests, however, were conducted with the standard RO920 M4 Carbine, not the SOF RO921HB M4A1.

Would that have made a difference? Who knows, it's almost impossible to say - but the SOF RO921HB is not 100% the same weapon as the RO920. The biggest difference being the buffer and barrel profile (barrel profile being significant to bolt bounce, which is important in fully automatic fire in particular).

As for the "popular culture review," which is used in the heaviest fighting versus which is being mostly carried rather than fired? Arguably, the SOF guys and light Infantry guys of any component are the ones doing the most firing - both in training and in combat - and most of them, Marines included, are using M4s or M4A1s.

~Augee

Yea, Marines use M16A4's extensively, in Iraq and Afghanistan and have been almost the entire GWOT (after replacing the M-16a2's used in the beginning).


Said variants have been used in some of the heaviest fighting in the GWOT, including Phantom Fury which is the largest fighting Marines saw since Hue in Vietnam.


To say that "...and most of them, Marines included, are using M4s or M4A1s" tells me you don't know anything about what the Marines use or where.


The M-16A4 is the Marines service rifle. Not the M4.

You've selectively quoted me and in doing so twisted what I said. What I said was:



What do the MSOBs and FR use? I would consider them the Marine Corps SOF and elite light infantry guys.

I am well aware that the MTOE service weapon for conventional Marines E5 and below is the M16A4.

I am also aware that somehow or another, a very good number of conventional Marines, including those below E5 are getting their hands on M4s to use in theater.

I have not suggested that M16A4s are not seeing *any* combat. However, I stand by my statement that those weapons getting the heaviest workouts - in both pre-deployment and combat as individual weapons, are carbine variants.

"In general," and I do use this sparingly, I am aware of the engagements involving Marines using both M16A4s and M4s, but in general, conventional kinetic engagements involving conventional formations are not necessarily abusive to the weapons involved. The "largest battle" doesn't necessarily mean that everyone has got their selector levers flipped 180 and rockin'-and-a-rollin'. I am not taking anything away from the Marines involved or the weapons they used.

What I would challenge, however, is that Phantom Fury, or other large-scale combined arms battles are really a "reliability test" for individual weapons *compared to* a small FR or MSOB element that is conducting a raid or gets ambushed or any other scenario that might befall a small-unit SOF element that would result in enemy engagement. I would suggest that these small units, almost all equipped with M4A1s, whether they're Marines, Soldiers, or Sailors, in terms of rounds expended per person, cyclic rate of fire, number of enemy versus number of friendlies, exceeds the strain on the individual weapon compared to that of a conventional soldier of any component equipped with an M16.

Furthermore - prior to ever setting foot downrange, these specialized units are putting more rounds down range and pushing their weapons further than conventional troops generally do.

Since the "scientific" claims of the Army and Marine Corps directly contradict each other - they're a moot point, at least until further testing is done. Or, you can choose to believe one over the other for your own reasons, which you're entitled to do.

What I pointed out is that based on sample size - 14.5" carbines have been in use since 1973 by SOF and have been continually evolving to meet the rigors and demands of SOF deployments and training cycles - while the M16A4's internals are, for all intents and purposes identical to that of the M16A1 of 1965.

In 1996 a study done on the potential for barrels to burst under heavy automatic fire concluded that the M16A2 barrel was just as likely to burst as the M4A1 barrel. It was not considered to be a significant advantage to update the M16A2's barrel. All SOCOM M4A1s were retrofitted with HB profile barrels - based on the expectation that the M4A1 would be more likely to experience abusive firing schedules making it a worthwhile investment to have all the barrels in the inventory retrofitted, while the M16A2 and M4 Carbine could remain in their current configuration since even when heavily used, they did not present with barrel integrity problems.

Is this because they're better? Or because the M4A1s got used more and more heavily, making the chances of failure higher, even with a smaller population in service?

I believe that as a whole this continues to be the case, that for every bit that conventional forces have increased their training and pre-deployment round counts, SOF has as well. For every engagement that conventional forces using standard weapons have been in - M4A1s have been in more, and heavier engagements that were more abusive to their individual weapons.

The vast majority of concerns "in the popular culture review" with notable exception of Wanat - an Army COP, the Army's Standard A being the M4, are concerns originating from SOF units, not conventional ones. So are these M4[A1] problems then because the M4A1 is inherently inferior to the M16A4, or simply because the end-users are using M4[A1]s? In general in-service opinions of the M4 are high and reports of failure low.

Finally - I never said that the M4A1 is "definitely better" or "definitely more reliable." Not only did I qualify that it was "arguable," which you've taken me up on, but I simply said:



I still maintain that. I believe the M4A1 has been used harder for longer on a per-weapon basis than M16A4s, and has returned a solid and impressive performance record, more so than any other M16FOW based system.

I also ended that post with:



Just to clarify that test results have been inconclusive and/or of too small a sample size to make a definite call on which is "better."

I just think the M4A1 has proved more than a worthy successor. You needn't share my opinion, I was simply offering the OP another take on the question, "how's it better?" I don't think it is.

~Augee

OHHHH I get what you're saying I think.




That if you boil everything down to what specialized forces use vs. conventional forces use the M4 is better because the narrow focus excludes the A2/A4.



Also FWIW, the M4 is a Carbine version of the M-16a2, so your whole date comparison thing doesn't line up like you want it to.

Testing was done by both the Canadians and the USG to determine the reliability of the M16 with A2 and M4 stocks and the M4. When shooting millions of rounds the M4 was less reliable but not meaningfully so.

To me it seams as long as the MFBR is a few times more than a combat load, it's really nit picking.


As someone pointed out in a thread like this a long while back amidst the M4 dust test controversy; it's not about how many rounds it failed to fire, it's about how many they fired successfully.

Sure, if that's the way you want to read it, have at it.

So you disagree then that by and large, special operations weapons get a harder work out than those used by conventional forces? Or that this use constitutes evidence of performance?

If you don't disagree, then for whatever reason, the A2/A4 is excluded by this limited focus, because if weapons are going to be used to and beyond design parameters to failure, it's most likely going to be by SOF, hence, there's more direct evidence, not theoretical or anecdotal evidence. It's not to say a rifle length system or midlength system couldn't perform on that level - it's that they haven't. If you look at the population of M16FOW based weapon systems that have been used to failure in the last forty years, they are overwhelmingly of the 14.5" carbine type, not the 20" rifle type.

FWIW - the R653, or M16A1 Carbine has been in use since roughly 1973 and was adopted to replace 11.5" barreled XM177E2 types. When Colt updated their commercial line with M16A2 Carbines, so did the military, using several COTS variants such as the RO723 and RO727. Development of the RO720 / XM4 began in the 1980s. The RO920 was type classified as the M4 Carbine in 1994, with the RO921 following in 1995 as the M4A1 Carbine. The current issue RO921HB didn't come about until 2000. Internally, the R653, RO720, RO727, and RO921HB are all different, if subtly, and have undergone a good bit of development since 14.5" carbines first arrived on the scene.

I'm still not entirely sure what or why you're trying to argue, or are you just trying to argue?

~Augee

So, wait, is the M4 variant tougher because it gets used harder by SOF units, and sees routine upper echelon maintenance, or is the M16A2/A4 tougher because it's not used as much, but never see's upper echelon maintenance and continues to function?

Does this mean that the true measure of how reliable something is should be how long it had to be studied to make it work?

I bet just by volume the M16 has fired more rounds than the M4 and high round count examples of both exist. We know from comparison studies that if you fire an equal number of each several hundred thousand times you will experience more malfunctions and a shorter service life with the little one.

I still maintain that the measure of a rifles success is how much bad press it gets.


The M4 caught a LOT of flack, so did the M-16. Yet late model M-16A1's and and M-16A2/4's (and M16A2 uppers on M-16A1 lowers) humm right along with nary a blip on the medias scope.

I know that, you know that, but it's more fun to rule out as many variables as possible in order create a sample that supports a pet theory.

I'm sorry, I'm afraid I'm still not sure what you two are arguing. What is my "pet theory" again? If I'm going to argue it, I may as well know what it is.

Please indicate for me where I have a) suggested that the M16 was "unproven," that b) the M4A1 suffered fewer MRBS/F than the M16, or c) that the M16A2/4 would be unable to perform to the same level.

My first and only argument has been that the SOF M4A1 platform has been run harder and more abusively than the M16A2/A4, and by virtue of that level of use, it can arguably be said to be more proven. There is more to reliability and performance than MRBS/F. For reasons you've both pointed out, actually, I think that past a certain threshold (several times a realistic combat load), it's actually one of the least important factors. My argument that in a question of subjective "better," for me "has demonstrated its ability to do it" trumps "theoretically should be able to do it better."

In response, the only factual evidence you've so far given has been "Operation Phantom Fury is the largest Marine Corps battle since Hue." Your other posts have been either sarcastic with no content, or of the "survey says," "well the media doesn't write about," or "well *I* think" variety. Inferential, conjectural, and you haven't given any solid reasoning for your thinking so.

Nevertheless, I'll reiterate a point I've already made, in case you missed it, since I don't think I've seen a sarcastic comment about it yet:

The 1996 SOCOM test in response to M4A1 catastrophic barrel failures, which were occurring in small but alarming numbers concluded that the M16A2 barrel was just as, if not more likely to suffer from catastrophic failures (burst barrels) as the original M4A1 (current M4) profile barrel.

Given that the M16A2 barrel profile is identical to the M16A4 barrel profile - would it not stand to reason - that if the M16A2 or M16A4 were being used as heavily and as rigorously as the M4A1 was in 1996, that there would be a similar small but more than coincidental number of catastrophic barrel failures reported? Would there not be a realistic enough reason to retrofit existing M16A2s and A4s with re-profiled barrels to prevent catastrophic failures as there was with the M4A1?

To my knowledge, there are not significant reports of M16A2 or M16A4 catastrophic barrel failures being reported today to the extent that there were for the M4A1.

Which would seem to suggest either:

1. The 1996 SOCOM test - which was originally intended and expected to "prove" that carbines were more prone to failure than M16A2 rifles was incorrect, and in fact, M16s are simply more resistant to catastrophic barrel failure, even though they're being used just as hard or harder than M4A1s were sixteen years ago.

-or-

2. M16A2s and M16A4s are simply not undergoing the types of rigorous, abusive, and heavy firing schedules than the M4A1 has been subjected to since at least 1996, and therefore fewer data points that indicate how the M16A2/4 performs under these conditions exist in comparison to the M4A1.

Re-stated - if M16A2/4s are being used just as hard as pre-2000 M4A1s, and pre-2000 M4A1 barrels and M16A2/4 barrels are equally prone to catastrophic failure, how come M16A2/4 barrels aren't bursting at the same rate that M4A1 barrels did before being redesigned?

When you respond, I would appreciate if you'd do so with either factual evidence or a well reasoned argument, not hearsay, conjecture, and snide comments.

~Augee

I only fire 58 rounds a year from my M16. So I'm hardly doing my part...

The obvious answer is that there is no auto selector on the A2.

Well at least your avatar does...

dalyman the only logical thing to do is to fck the A2 and get a M4A1

So... the A2 is mechanically limited from being pushed as hard as the M4A1 and therefore mechanically limited from being proven under comparable conditions?

It's been a while since I pulled up the exact reports, but my understanding of the catastrophic barrel failures associated with the early M4A1s were not a matter of continuous automatic fire in the way we think of destructive testing like the "infamous" videos where a rifle is clamped into a rest and just shot in auto until something breaks. If nothing else, I fail to see the training value in that kind of firing.

The barrel failures of the M4A1 that prompted the test, regardless of how the test was performed, were not destructive testing - they were something that happened during the course of some sort of training, whether FPL or break contact scenarios, something that could be hypothetically done with a burst function as well.

~Augee

I think the implication and assumption that I'm "dumping" on the M16 or suggesting that the OP shouldn't get one is unfair - I've owned five 20" rifles in my life, and still have three, and love the crap out of them - and yes, of the three 20" rifles I own, the A2 is my favorite, because it's what I first learned to shoot on as a nineteen year old Yankee from liberal suburban New Jersey. It's still the one I prefer to start new shooters on, unless they're really short females - in which case it's an RO723 - a fixed carry handle carbine clone.

I guess what I did was to "dare" to crash the "A2 love-fest" by offering a different perspective and implying that "the A2 is better" was not a foregone conclusion.

~Augee

no didn't mean that at all just if he gets a happy switch M4A1 i may get some trigger time

Or, you know, for reasons pointed out, the A2/A4 platform does not endure the same stresses of operation that the M4 does.




Makes one wonder how the A4 will handle M885A1 vs the M4 over time?

MY M-16A2 went through 2 deployments, tens of thousands of rounds, still netted me expert every year out to 500 yards, and never saw a day of maintenance during my time in the fleet, and probably didn't with the Marine that had it before and after myself. That's everything from the KD range, to shoot houses CQB/MOUT courses to dumping mags as fast as possible at the end of a range day so there was no ammo turn in (to the point I was having cook offs) to deploying in Iraq and hammering rounds out.



Sure M4a1s in the hands of SOF types get High round counts. That's also why they have unit armors.



SOF is the MINORITY user though. Comparing a minority user of a certain platform that has a high level of support, to a service wide version of a weapon that still gets high round counts, but over a longer duration, with magnitudes worse maintenance is comparing apples to oranges.

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