Vets: Full Auto vs Semi Auto?

In my experience, semi-auto fire was the best for 95+% of the time, with full-auto fire for the balance. The three round burst was kind of an odd duck, and not really good at either scenario. Unfortunately, full-auto was not available in the standard M16A2 and early M4 era, with my service also including some M16A1 time.

JCooperfan1911 said:

How effective is it vs carefully aimed but slow semi-automatic fire?

Click to expand...

Effective at what? Area saturation, suppressive/cover fire, acquisition/elimination of a single target?

My understanding is that full auto is mostly useful for belt fed machine guns to create a base of fire so that others (usually with lighter weapons) can maneuver against a target. While full auto from a standard infantry rifle (M16 / M4 / AK) can be useful, it would mostly be useful only in very close quarters (and often times the weapon would still be used in semi-auto).

The AK being used like a submachine gun is more about the doctrine and tactics of the Soviet Union at the time, rather than about the gun itself. In WW2 the Soviet Union used a lot of submachine guns which were predominantly used in full auto because with a pistol caliber, you really want a lot of volume. The weapons trials that the AK 47 won were actually to find a replacement for the various submachine guns in use at the time, so at least initially the AK was expected to be used in the same role as the old SMGs - namely in full auto at close range.

From a modern western/US small unit tactics standpoint the goal is to use one unit to pin down the enemy while another unit flanks/closes with that enemy. To do this, you need effective fire (or fire that makes the enemy think they’ll be hit if they move from cover) which means accuracy is preferred rather than pure volume. Once you have an enemy pinned (where machine guns are very helpful), one round every 3-5 seconds that is very close is better than 5 rounds in FA where half are nowhere near hitting the target. That also means less ammo is used, which translates to being able to keep the enemy pinned for a longer amount of time.

As an aside, things get interesting once you start thinking about the ammo you’re carrying in terms of “how long can I fight” versus “how many rounds can I fire”.

It’s really just an issue of preferred military doctrine. If US troops were handed an AK instead of an AR, they’d still use it in semi auto the vast majority of the time.

For me, semi was for accuracy - auto was for speed and intimidation. Very much a guess on my part, enemy headcount was much higher on the semi side of the ledger.

Larry Vickers has a good video on this subject

IMHO the benefits of full auto fire are "greatly exaggerated" . In WWII the Soviets issued large numbers of their PPSh M-1941 and PPS M-1943 submachine guns, easy to manufacture, easy to train conscript troops with, Soviet tactics emphasized keeping close contact with the enemy, and letting artillery do the real damage. In Vietnam troops kept their M-16s on full auto as a matter of course, the thick forests and dense jungles made marksmanship problematical, likewise the preference of the VC/NVA for night action. Like a shotgun, people think all you have to do is point and pull, put enough lead in the air, you'll hit something.

I've never been in combat.

I was XO of a basic training company in the '80s.

When the trainees were shooting full auto at staked balloons at night, the safest place to be was among the balloons.

As long as you've got something like an M249 or Ameli, full-auto rifle fire is pretty much a waste of ammunition outside of banzai charge distances.

Years ago, I read one of Jeff Cooper's articles concerning this subject (in either "Guns and Ammo" or "Shooting Times").

He was acting as a consultant for, IIRC, some foreign dignitary/politician/entity. The foreigner had his personal security detail armed with submachine pistols. Mac 10s, I believe.

Mr. Cooper was there to show the limitations of full auto vs the superiority of controlled semi auto fire, viz. the 1911.

The foreigners were duly impressed with Mr. Cooper's skill and accuracy and also disappointed in the inefficiency of full auto. According to the article, they ultimately abandoned the submachine pistols in favor of semiauto handguns. Mr. Cooper trained them in such.

Not exactly what the OP is asking, but it's sort of germane to the discussion.

Maybe somebody else also remembers the article and can clean up my misremembrances? I've slept since then.

(Kind of ironic since the OP's avatar and screen name pay homage to the late, great Jeff Cooper.)

Full auto is perfect if you have a bunch of ammo that needs burned up to keep from turning back in.

There is one benefit to automatic fire, and that is to lay down cover fire. Until recently the the light machine gun was the tool for that. The M60 and the Squad Auromatic Weapon played the cover fire roll. Of course when assaulted in direct force they were used to mow down as many enemy as possible. The army still uses the Saw I. Each squad. It is now developing a replacement for the saw. The Marines have shifted gears on that path. They have dropped the SAW at the squad level. Instead they have armed all infantry with the M27 which is a better platform than the M16, M4 for auto fire. The idea is that the M27 gives every fire team the ability to lay down cover fire as they maneuver. That is important because maneuverability is critical to the Marines way of fighting. Along with the M27 the have redesigned the squad going from 13 to 15 personnel. They have also equipped the M27s with a suppressor to reduce noise so commands can be better heard in a firefight. These changes have to due with the new role of the Corps, going back to its WWII roots as naval infantry which requires light weight power. It has dropped tank outfits transferring them to the Army. Ever Marine squad nor was a tow missile aboard to take out tanks and other large targets.

If an individual is properly trained, and recurrently trained, full auto can be useful... but not against individual targets. I generally agree with Deanimator's comments above.

In Army Basic Training, 1986, one of our rifle courses was the 'interlocking fields of fire' range. There was about 20 or 30 of us laid out prone, on full auto and 100% tracers at night, firing criss-cross applessauce. Oh, it was impressive, but it was unaimed fire, and all of us firing in concert... not something that can usually be orchestrated on a hot battlefield.

Deliberate, aimed fire is always the better solution.

Agree with most of the prior info posted. All I’d add is full auto fire would be a huge liability for the vast majority of shooters. I’ve only shot full auto twice, and both times it was fun but much less controllable than our TV and movie gunslingers would lead us to believe.

A VN veteran told me that his outfit's doctrine was, if ambushed, to dump a magazine at the ambush as you took cover, then reload, select semi and look for individual enemy.

I was a combat engineer so our training and doctrines were s little different than infantry units. For the most part, we left the full auto fire for the belt fed machine guns when we still had the M16A1 rifles. Yes we did have a need to use the M16A1 on full auto on occasion. I spent a majority of my time as the squad 60 gunner.

Now for a little bak story on the M16A2. The bean counters had quite bit to do with the M16A2 being 3 round burst. That and it was also found that full auto wasted a lot of ammo during Vietnam.

Part of the reason for doing away with the 3 round burst for full auto on the newer M4 carbines is for better accuracy in semi auto fire. If you compare the trigger pull on a M16A2/A4 or M4 with burst to A1/A3 rifles and M4 carbines with full auto, the full auto versions have a better/smoother trigger pull on semi auto. This actually helps improve accuracy. This is by far not the only or main reason to go back to full auto.

Buzznrose said:

much less controllable than our TV and movie gunslingers would lead us to believe.

Click to expand...

Much less believable when said actors (and actresses) forget to add recoil to their firearm. Seeing some 98 pound cupcake firing a big bore rifle full auto, yet the muzzle never rises, never fails to amuse.

This discussion highlights the fact that the National Firearms Act, with its emphasis on "machine guns," has become largely irrelevant. Fast, aimed semiautomatic fire, in most cases, is more effective than fully automatic fire. Yet the NFA is stuck in the mentality of 1934, which was before the adoption of the M1 Garand and then a host other effective semiautomatic weapons. In other words, technology has bypassed the NFA.

Maybe the presence of the NFA (including the Hughes Amendment) is a good thing, though, because it gives the impression that such weapons are regulated. Meanwhile the development and distribution of semiautomatics goes on unabated.

Not mil, but I know and have trained or trained-with, plenty. We talk. But they are not on this forum: Essentially everyone hates even burst fire, wants semi-auto for all carbine work. It's all aimed, and even "suppressing" fire is just a number of individual aimed shots at a vague or invisible target.

But.

The MGs break (okay, usually just suffer stoppages that take a while to clear) often enough, and it's easy to imagine worse issues in a more protracted peer fight, that they want all rifles to be ABLE to go full auto. Then the team/squad leader can point at someone and say "you are the machine gun," to someone who can handle it, and he moves to a useful position, acts as their base of fire even though only an auto-rifle. Some units that do this have a TTP for anyone nearby and able to donating a few mags as they pass by on the assault, because a carbine loadout gets expended quick as an auto-rifle.

I know people who have done this in combat, have sometimes interesting stories of what happens when you stress test your carbine. It also is the purported (though pretty reliably) reason for the heavier SOCOM profile (but for 203 cuts, heavy all the way back to the receiver), to give a bit more mass for the relatively more common usage of the carbine as an ad-hoc auto-rifle.

First Person Account:

> "... When I was caught in the open when they attempted to block off the road and catch us in a cross fire,
> I was in the lead and dismounted. There was no cover. It was a split second decision, but I charged them,
> firing a whole magazine into them as I ran. Two seconds into my charge the 50.cal from the truck behind
> me let loose and tore up the enemy vehicle. I saw two of the fighters in the back go down from my fire.
> The enemy truck sped off (i don't know how it was still holding together), but we intercepted it a minute or
> two later ..."

Full-auto option... when needed.

.

JCooperfan1911 said:

Thank you. If the rolls were reversed and your unit was issued with AK-47s for example, would you still say those numbers would apply?

Click to expand...

I wouldn't think there would be much change, as the AK sure doesn't have better accuracy over the M16 in full-auto fire.

AlexanderA said:

Maybe the presence of the NFA (including the Hughes Amendment) is a good thing, though, because it gives the impression that such weapons are regulated. Meanwhile the development and distribution of semiautomatics goes on unabated.

Click to expand...

The NFA is no more of a "good" thing than the Fugitive Slave Act.

Violation of rights is violation of rights, no matter the far fetched justifications conjured up to excuse them.

Your basic combt load used to be 180 rounds. (88-95). Using the 3 round burst ate a lot, but you would be out altogether using full auto. Full auto allows no control. Even 3round bursts gets you off target quick. Not that you focus much in combat.

About five decades ago I was a Marine infantrymen. The issue weapon (rifle) for infantrymen at that time was the M16E2 (if memory serves). That was the basic M16 rifle, chambered 5.56 NATO, fully or semi-automatic (at user's option) with forward assist.
At that time, aimed fire was considered the basis of using a rifle. Fully automatic fire was offered as a sop to those who could not shoot and feared their inability. The later three shot burst option was used to turn a "one long shot" weapon into a ten shot weapon while giving some comfort to the terminally incompetent.

The whole concept of infantry level gun fighting is rather complex and intricate. A few sentences will not be sufficient. The idea of firing wildly while hiding is not really effective. Testing shows that regular troops cannot hit five silhouette targets at twenty five yards using a fully automatic rifle (Stoner 63 in belt fed, hand-held mode). However, armed with semi-automatic arms (same rifles), most could hit all five targets with five shots at one hundred yards.

I am staunchly against fully automatic fire for infantrymen. It does have some function for perimeter defense, and seems effective in aircraft use.

I would point out the only reason the M16 was at all useful in Vietnam was it's employment as a submachine gun rather than a rifle.

No doubt some will disagree.