quote:

Originally posted by KSGM:
The M1 Carbine is not in the same class as the AR.

In which way?

Is the .30 carbine not ballistically inferior to the 5.56? Would a contemporary military be adequately equipped, if it's infantrymen carried M1 Carbines?

This message has been edited. Last edited by: KSGM,

quote:

I know the AR's modularity is what draws so many folks in, right now. That modularity wasn't there, when the rifle was first adopted; it's there now because something else gave the rifle an edge out the gate.

You did state this in the leading post. Threads tend to drift, but I will address it. What gave the AR/M16 the edge was 5.56. The AR10 had advantages but chambered in 7.62 its mechanical improvements weren't appreciated much. Few new designs are, Glock took a public trashing for introducing polymer, SIG for it's FCU design.

Nope, what got the soldiers interested was as said, light weight. And that only comes at the price of using a much smaller load. Pushing the .22 bullet at 3,000 fps meant significantly less recoil. And recoil as perceived by the soldier is a known documented impediment to shooting. How many take 500 rounds of 7.62 power level ammo to the range for an afternoons leisure? FEW. And this was well known, even before the days of .30-06, and WWI was a marker. The armies brought tripod mounted machine guns for volume of fire, the bolt guns were awkward about delivering it, and the users even more so.

In the 1930's it was already being addressed and the result was the .276 Pederson - a reduced recoil round with the same class lethality as 5.56. These are considered "intermediate" power level rounds but the casualties produced were significantly higher - because it was quickly noted the shooter was a lot more enthusiastic about pulling the trigger again - and again. .276 was not to be, logisitics and Ordnances' Not Invented Here mindset blocked acceptance. Along with a detachable magazine - consider what WWII could have been like had we gone in with those. The Germans had the same developement track when they came up with the STG - a short intermediate cartridge, which only came in 8mm because "logistics" demanded using the same bullet making tech. That design got copied into the AK47, another intermediate round using the already accepted Russian 7.62 in a low recoil case. Compared to their previous bolt action/MG round.

Low recoil ammo is where the AR made it's biggest impact. Low recoil aids the shooter in shooting again, shooting more accurately, and shooting more bullets means more flying in the air which means more hit the enemy - even when not directly aimed at one. Manuevering on the battle field means troops actually move into the bullets flight path more often than an aimed shot. That is what Army combat research kept coming up with - and the counterintuitive approach was to come up with a less DRT round which the soldier would keep firing. Not aiming waiting for a static target.

Most hits are at about 125 meters, which does correspond with how the .30-30 works - another intermediate - and the results - the decimation of the American whitetail herd in America prior to 1940. It worked so well hunting season closed in many states. And adopting the 5.56 in the M16 is how we increased frequency of fire - most rules of engagement weren't full auto, despite the newsreel footage in Vietnam - and frequency of fire is how you quickly defeat the enemy in close combat, like ambushes. If we can't carry MG's on tripods to deliver it, then encourage the soldier to do it with the best possible sales approach - let them want to shoot the gun again. And again.

5.56 is what made shooters want the M16, and it also what so many in shooting matches kept it out, right thru the 1980s. It wasn't until then that Service Rifle showed it's merits - on the same targets same number of bullets shot, the M16 would gain a net higher score, mostly in the rapid fire phase, where it was shot more quickly, more accurately. And that is why the M16 still dominates Service rifle against all the .30's, 3Gun has the same results. It was a sea change when shooters accepted the results instead of insisting more push ups would change the balance of fighting. More push ups never did before, and haven't yet.

Which would you rather shoot 500 at the range? 7.62 or 5.56? I see the latter actually done much more.

So, in comparing a 5.56mm fighting rifle to a 5.56mm fighting rifle, does an M4 carbine have an edge over something like a HK416?

IGNORING modularity/modification potential and price.

It's kind of hard to argue about weight - or sveltness - without talking about purpose. If given the choice between a lighter rifle and a heavier rifle, I'd generally choose a lighter one. But a lighter rifle heats up more quickly and may get dinged up more easily, even when used for something as prosaic as crawling through the bracken to shoot feral hogs.

Therein, IMHO, lies the virtue of modularity. The basic design can be tuned to a purpose or range of purposes.

As for an M4 vs an HK416, it's hard for me to say since I haven't shot either. I can say, though, that a 16" Armalite in 7.62x39 is lighter, handier and physically a little easier to shoot well than a semiauto AK.

This thread started because I was considering the virtues of piston operated designs. A typical byproduct of a piston design is extra weight and bulk. Do most of us compromise on potential positives of a piston gun, in favor of the AR's light weight? A Colt 733 compared to a Sig 551 would be another good example. Keep in mind that this is the gun in it's raw form.

quote:

Originally posted by KSGM:
An M1 Carbine is lighter than an AR for the same reason it's lighter than a Mini14; a Mini14 is lighter than an M14 for the same reason as well. The M1 Carbine is not in the same class as the AR.

The 22 Spitfire or 5.7 Johnson was a wildcat round, 30 Carbine necked down to .224 caliber pushing a 40 grain bullet at 3000 fps. It only required a new feed ramp & barrel. So once again, why does an AR that should be lighter than an M1 Carbine weigh more?

Well, the only rifle i own in 556 is an SG550.
Ive owned a few different rifles over the years (SVD, FAL, AKs) I've never owned an AR though.

quote:

Originally posted by KSGM:
This thread started because I was considering the virtues of piston operated designs. A typical byproduct of a piston design is extra weight and bulk. Do most of us compromise on potential positives of a piston gun, in favor of the AR's light weight? A Colt 733 compared to a Sig 551 would be another good example. Keep in mind that this is the gun in it's raw form.

IMO, that is completely dependent upon the use case. I personally have no use for a piston AR. DI guns are perfectly reliable for my purposes, and as such, there is no benefit to me to opt for the heavier, more expensive piston system over a lighter-weight DI gun. But if somebody was going to be doing a bunch of full-auto shooting where heat buildup in the upper might become an issue, or suppressed shooting where they want to mitigate gas to the face, then a piston gun might offer some benefits to them. Whether or not it's enough benefit to overcome the downsides would be up to that individual to decide. But this brings us back to the modularity issue...the fact that the AR is modular is a huge feature of the gun...you can even alter the core of the operating system and still remain within the same platform (kinda).

Direct Impingement is a fancy way of saying how the M16 works, in reality its little different than a piston gun. A piston is basically a gas cylinder, the moving part is the piston which then transfers impulse to the action. In DI, there is a gas cylinder - the bolt carrier - with a sealed end - the bolt with rings - and the moving part is the cylinder, not the bolt. Aircraft engines were built the same way, some rotaries would fix the crankshaft to the frame, and the cylinders would rotate with the prop attached to the center block. It doesn't have to be just one way only.

That makes the M16 a moving cylinder gun, not a piston gun. It eliminates the action strut and simplifies a lot of other things, too. Therefore, lighter. Now, in the AR10 shooting 7.62, the larger barrel, heavier action parts, etc will still give a net savings in weight - but that only makes recoil a bit heavier with less mass to soak it up. The AR10 was sold and used by two other countries but overall wasn't appreciated for much beyond its unique features. The shooter was still dealing with recoil, and 5.56 - an intermediate cartridge - is what made it work.

The bulk of the world's armies quit using "full power" battle rounds and they are mostly crew served weapons now, not individual arms. Low recoil is the dominant choice now and we won't return to higher levels for quite awhile - the new 6.8 composite is being fielded in switch barrels for light MG's and a lot of the ammo demostrated is belt feed. With a 30% lighter weight that is an advantage army wants to exploit sooner than later - but the case length won't feed in the M16 family. Replacing millions of M4's and M16's won't happen soon. What could happen is 5.56 Composite being fielded while they are still in service.

it's up there:

light weight
low recoil
decent terminal effect / power
accurate
reliable (after they got the initial bugs worked out)

as you mention -- the modularity came later enhancing an already proven design

but the 'light weight' part is a huge factor for infantry forces.

an incredible design by Mr Stoner that has withstood the test of time and like a Glock is the standard by which other designs are measured

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With many people’s focus on a rifle’s weight this is another interesting discussion to me because its being as light as possible isn’t something I’ve ever thought about.

First, a disclaimer: I recently watched a video about the Magpul PRS Lite stock in which the reviewer was a competitor who (evidently) had to regularly carry his carbine for long distances. Some professional gunmen like soldiers or SWAT team members must do the same for real or in training. For those men I can see why weight would be a factor. But what about the rest of us? Why is minimum weight in such a gun so important?

From the standpoint of practical utility and we’re not humping it far more than shooting it, I can think of one advantage to a lighter gun. That’s when making transitions to engage more than one target as fast as possible. A lighter gun is easier to get moving and it’s easier to stop its movement. If that were the only consideration of a rifle’s weight, then that would be enough to keep it as light as possible. But it’s not.

The first advantage of a heavier rifle is the effects of recoil. The 223/5.56 cartridges don’t produce much recoil, but they’re not like an airgun or airsoft gun whose recoil is virtually nil. The recoil they produce does affect the shooters’ ability to get multiple accurate hits quickly and no matter how skilled we are at using techniques to control recoil, a heavier gun makes it easier.

A heavier gun also reduces the discomfort caused by the recoil. That may not be a factor for the vast majority of shooters, but it is for some. Until I changed the stock of my most recent acquisition, it was unpleasant to shoot from the prone. The large, healthy husband of one of my nieces found shooting an M4 style carbine unacceptably uncomfortable. I don’t want to overstate the effects of recoil when shooting such low-momentum cartridges, but it’s not nothing. If I were introducing a 10-year-old to centerfire rifle shooting I’d start them out with my Tikka T3 in KRG chassis rather than an AR carbine. The greater the recoil that is felt by the shooter, the more of a distraction it is and hindrance to becoming a skilled marksman.

A more important advantage of a heavier gun can be its practical accuracy. For a skilled shooter, a heavier gun is easier to keep steady because its greater inertia dampens the small involuntary movements our bodies make when trying to hold it in position. That’s not a matter of doubt or controversy because it’s what precision target shooters who must hold their rifles without artificial support have known for as long as such shooting activities have existed. My Winchester model 52 22 Long Rifle target rifle has a massive 26 inch barrel and weighs close to 12 pounds with its Redfield 3200 scope.

And if weight doesn’t matter for that reason because the shooter never fires the gun without artificial support, it can be a benefit in spotting one’s own hits. That’s at least part of the reason long range shooters of the Precision Rifle Series type add extra weights to their guns. A heavier rifle may not be an advantage for those reasons if all our shooting consists of mag dumps into the berm or engaging IPSC-sized targets at 50 yards, but that’s not true of everyone (and shouldn’t if we’re striving to become a competent rifleman).

If I’ve managed to miss something about the weight of a gun like an AR rifle or carbine, please educate me. Again, I’m not referring to the obvious advantage of a gun that is as light as it can be made if it must be carried for long distances for competition, hunting, or professional purposes, but for the more common activities that most of us engage in.

This message has been edited. Last edited by: sigfreund,

I'm sure an SG550 is somewhat controllable in full auto, although I haven't had that pleasure.

Politics aside, I just can't trust my life to an AR worse case scenario.

quote:

Originally posted by Tirod:
much more.

Great comment. Thanks.

When the military made the switch to the M16 it was due to several factors: rifle weight, ammo weight and ammo capacity. Studies showed that most bullets fired in battle never hit their target so they went with a weapon system that was lighter and allowed more ammo to be used per soldier as suppressive fire so the enemy could be flanked or an airstrike/artillery could be used to finish them off.


If the M16 kept its original form and was made semi-auto only it would be just another military rifle converted for civilian use. There are other .223 rifles that fill that role and at that point it's simply a matter of preference. The fact that it evolved into the M4/AR-15 is what makes the AR-15 the best. And it is the best.


The AR platform does it all due to its modularity and that's its best feature. Because of its modularity aftermarket accessories took off and nothing even comes close. Weight? Not even a consideration when I bought mine. I wanted multiple calibers, barrel lengths and optics and I got it on a single platform with the push of 2 pins. Whatever weight savings could be had going with something else wasn't worth it. Just my 0.02

So, using 92fstech's post as an example, it seems clear to me that most people perhaps don't require the advantages of a piston gun, and would therefore prefer a lighter weight weapon. Ignoring modularity and cost, the plus side of lighter weight does seem to edge out positive characteristics of piston designs, for most people. I think the comparison of the 733 to the 551 is a good one. Both are similarly capable ballistically, but the 551 is inevitably heavier, due to the long stroke piston operation.