Auto/semi-auto/3-round bursts?

[deccantrap]

Can someone explain to me what is the exact different between fully-auto/semi-auto/3-round burst modes?

I thought I knew but I got confused after I read somewhere (maybe it was wrong) that the AK can basically empty out its magazine if you keep the trigger depressed while the M16 cant. Which set me thinking if M16s are inferior in firepower vis-a-vis AKs.

Can you also tell me what kind of fire types (auto/semi-auto/3-round) are the following guns:

AK-47
M16A2
M4A1
M4 Mod
SA80

Thanks.

[DeltaWhisky58]

OK: Assuming a selective fire weapon with these settings.............

Semi-auto - depress trigger, weapon fires a single round - BANG

Three round burst - depress trigger, weapon fires three rounds - BANG-BANG-BANG

Fully Auto - depress trigger, weapon continues to fire until either trigger is released or magazine is empty - BANG-BANG-BANG-BANG-BANG-BANG-BANG-BANGBANG-BANG-BANG-BANG-BANG-BANG-CLICK

[moonmonkey]

SA80 is semi and auto only

[Hydro]

AK-47 - Semi/Auto
M16A2 - Semi/3rb
M4A1 - Semi/Auto
M4 - Semi/3rb
SA80 - Semi/Auto

[Solo]

I've always wondered one thing about the burst mode.
Will the three shots be shot in every case, always, or depressing trigger quickly and releasing may just shoot one single bullet, or two?

i.e., will the weapon with a burst fire selection end its firing cycle no matter what, or there are exceptions?

[DeltaWhisky58]

I've always wondered one thing about the burst mode.
Will the three shots be shot in every case, always, or depressing trigger quickly and releasing may just shoot one single bullet, or two?

i.e., will the weapon with a burst fire selection end its firing cycle no matter what, or there are exceptions?

When you fire a burst-fire weapon, its firing cycle is two/three/however many rounds - that is the way the mechanism works.

[Frens]

I've always wondered one thing about the burst mode.
Will the three shots be shot in every case, always, or depressing trigger quickly and releasing may just shoot one single bullet, or two?

i.e., will the weapon with a burst fire selection end its firing cycle no matter what, or there are exceptions?
if you pull the trigger and then you release it quickly you can shoot just 1 or 2 rounds.
note: the 3 round burst on the M16A2 (and A4) doesn't reset!

[Solo]

Thanks to both of you gentlemen

[Frens]

you are welcome mate :hug:

when I said the 3rounds burst I mean that the trigger group does not reset when the trigger is released. If a soldier lets go of the trigger between the second and third round of the burst, for example, the next trigger pull would only result in a single shot.

[Solo]

you are welcome mate :hug:

when I said the 3rounds burst I mean that the trigger group does not reset when the trigger is released. If a soldier lets go of the trigger between the second and third round of the burst, for example, the next trigger pull would only result in a single shot.

HA. That I hadn't understood fully. Thanks for clarifying it mate ;)

[deccantrap]

Thanks for the replies. More questions on my part....

So is the AK-47 superior in firepower (not talking about accuracy here) than the M16?

Mechanically, what is it that makes it possible for the AK-47 to have a fully auto? Is it more expensive to make a fully auto rifle than a 3-round burst?

Why do most armies in the world issue 3-round burst guns as standard issue and not fully-auto?

-Thanks

[Frens]

M16A2,M16A4 and M4 have the 3rounds burst but M16,M16A1,M16A3 and M4A1 have full auto.

3rounds burst was introduced after the Viet Nam war only to limit ammo wastage by troops.
btw a lot of european armies' assault rifles have both Burst and Full Auto (also Safe and Semiauto of course) firing mode in the same rifle.

[RubyRidgway]

Can someone explain to me what is the exact different between fully-auto/semi-auto/3-round burst modes?

I thought I knew but I got confused after I read somewhere (maybe it was wrong) that the AK can basically empty out its magazine if you keep the trigger depressed while the M16 cant. Which set me thinking if M16s are inferior in firepower vis-a-vis AKs.

Can you also tell me what kind of fire types (auto/semi-auto/3-round) are the following guns:

AK-47
M16A2
M4A1
M4 Mod
SA80

Thanks.


As to Stoner's baby (M-16) being inferior to the AK in terms of firepower, the more heated debates will cover the choice of 5.56 for the M-16 versus the beefier 7.62 for the Kalash. The later M-16s (from what I've read) were switched to 3 round burst because of a whole lot of spray & pray in Vietnam, and something like 200,000 rounds expended for 1 VC or NVA KIA, I could be wrong. In terms of combat efficacy, controlled 3-round burst with a 20 inch barrel (another debate) in trained hands is definitely preferable to the relatively uncontrollable full auto the AK dishes out. Most armies see 3 rnd. burst as a more efficient alternative to full auto, and train their troops accordingly. And of course, 165 grains of .308 in the right hands can make a hell of an impact too.

[Hydro]

In terms of laying down sheer lead, yes the AK is superior to the M16A2. I believe it's merely the trigger sear that makes the difference between automatic and burst. I'm not entirely sure exactly how it works, I'm not an armourer. A trigger sear is hardly an expensive or complex piece of metal, cost really isn't much of an issue.

Most armies DON'T issue 3rb burst weapons as standard. The US is the only major player to do this. Most other weapons are either semi/auto or have semi/burst/auto. The US believed that automatic fire was wasteful of ammunition, probably due to lessons learnt in Vietnam.

IMO, automatic fire is very useful in itself, mainly for clearing confined spaces, rooms and trenches. If you want burst, just train up soldiers on how to use automatic fire in short bursts, or invest in a rifle with a burst AND automatic option. Limiting weapons to burst or semi only is nothing new - the Commonwealth countries did it with the FAL (semi only), to prevent ammo wastage and taking heed of the fact you can't hit **** with a FAL on automatic, unless you're reeeeeeeeeeeally close.

[Sabre]

Thanks for the replies. More questions on my part....

So is the AK-47 superior in firepower (not talking about accuracy here) than the M16?

Mechanically, what is it that makes it possible for the AK-47 to have a fully auto? Is it more expensive to make a fully auto rifle than a 3-round burst?

Why do most armies in the world issue 3-round burst guns as standard issue and not fully-auto?

-Thanks

1) Individual weapons are not meant to be the basis of firepower within a section/squad. A high rate of fire is provided by the section support weapon(s) such as the minimi or GPMG. Personal weapons (and by that I mean assault rifles like you have mentioned) are designed to be primarily used as accurate semi-auto weapons. The idea being that the support weapons keep up a high, suppressing rate of fire while rifles are used to accurately engage enemy troops, or likely enemy positions.

The AK is not, therefore, superior in firepower to the M16. Both are used with semi-auto (called repitition in the British army) most of the time. Automatic fire is only used when clearing trenches/bunkers on the 'fight through' or for anti ambush drills as both occasions require a higher rate of fire.

2) It is very simple to make a fully automatic weapon. The way a weapon works is that the first round is manually chambered by the action of cocking (or charging, if you are american) the rifle. The cocking handle pulls the bolt back and puts the return spring under tension. When the handle is released, the bolt goes forward and strips off a round from the magazine (which has its own spring pushing the rounds up). When the bolt goes back is also locks the hammer down ready to spring forward. When the trigger is pulled, the hammer is released and it strikes the firing pin in the centre of the bolt. This sets off the round and causes the bullet to shoot out of the weapon. The gases produced by the explotion are channeled back along a 'gas piston' which pushes the bolt back again, repeating the process of chambering a round and cocking the hammer back. When the weapon fires in repitition, a mechanical 'stopper' called a 'sear' drops into place to stop the hammer from striking the firing pin a second time. When the weapon is switched to automatic, this sear is held back out of the way and the cycle is allowed to continue unhindered, hence continuous or 'automatic' fire.

I don't know how a 3-round burst system works, but I imagine there is some sort of cam system or a series of 'sears' that stop the weapon after three cycles.

3) Most armies don't issue 3-round burst weapons. It is pretty much only the USA. There are bound to be some others but the majority of armies use repitition/automatic weapons. The reason why the US uses 3 round burst is because they found that all their soldiers wasted ammunition on automatic in Vietnam, so they resorted to introducing the 3 round burst instead of just re-enforcing the need for correct fire control discipline.

Hope that helps.

[Sabre]

Oops, got to learn to type faster!

Yes, 3-round burst is a bit of a waste of time. Any good soldier ought to be able to double-tap a target in the same amount of time. Automatic is more useful as you can give it a bit more welly if you need to and you still ought to be able to fire 2-3 round bursts with practice.

[Bulabash]

FNC has 3rd burst too, but we hardly ever use it on burst or full-auto as it is very unaccurate, burst is only used in FIBUA/MOUT

[gtronin]

re: 3 round burst, I was instructed to use it when engaging a moving target so when you lead a shot, you had a better chance of him running into a bullet...

[Son_Of_Suvorov]

It seems to me that the opinions reflected here basically reflect the ideas of what I like to call the two schools of the development of the assault rifle - one side (primarily American) viewed assault rifles as smaller rifles, while the other (primarily Soviet) viewed assault rifles as bigger submachine guns.


Personal weapons (and by that I mean assault rifles like you have mentioned) are designed to be primarily used as accurate semi-auto weapons. The idea being that the support weapons keep up a high, suppressing rate of fire while rifles are used to accurately engage enemy troops, or likely enemy positions.

Of course some armies have the concept of the marksman and DMRs or whatever you want to call them for this role.


So is the AK-47 superior in firepower (not talking about accuracy here) than the M16?

More powerful cartridge + full auto = hell yes! You can't argue with that.


A trigger sear is hardly an expensive or complex piece of metal, cost really isn't much of an issue.

Like Sabre said, a fixed-round burst system is actually much more complicated (which leads to problems) and expensive to manufacture than just select-fire sears.

Obviously, there is some need for a full-auto assault rifle in the US army, or else it wouldn't be there in the M4A1. Likewise, there appears to be some need (whether "correct" or not, I won't argue) for 3-round burst weapons. Most people don't know it, but Izmash has been producing the 100-series AKs (specifically models 101, 102, 103, 104, 105, with the designation AK-10x-2) with a 3-round burst mechanism for export since 1999.

Also, one thing that hasn't been mentioned here is that burst is good to have on weapons with very high rates of fire (which neither the M16 nor the AK have).

[Daga]

Firepower is hitting targets, not wasting ammo.

Just because an ak can go full auto, doesn't mean it is more "effective"...

FWIW, dumping a 30 round mag on semi is not that difficult... those 30 rounds can go fast, espcially under stress.

A SFC onced screamed at my platoon during a suppresion drill (battle drill 2a), "If your're on full auto, YOU ARE WRONG". Quite true, espcially since we were down to 30 rounds per person.

Full auto is for SAWs.

[CombatBoots]

Don't forget that the AK has got semi auto, and it can shoot well in that position also.

Full auto impresses the ladies and keeps the enemy low. nothing more

[Frens]

Don't forget that the AK has got semi auto, and it can shoot well in that position also.

Full auto impresses the ladies and keeps the enemy low. nothing more

^+1 on that

[Catch22]

Later polish AK clones such as wz.88 Tantal (5,45x39) and wz.96 Beryl (5,56x45) have separate safety/fire mode selector. There are 1 - 3 - full auto fire modes with 3 rnd's reseting (as opposite to M16 non-reseting burst).

Beryl fire selector lever in detail.
http://img.photobucket.com/albums/v179/Catch22/P8301227.jpg

[Vandervahn]

...Full auto impresses the ladies and keeps the enemy low. nothing more

One out of these two arguments is enough to justify a full auto capability ;)

[ironcross6]

the 3rd burst on the M16A2 is done by 3 sears or 3 notches in the sear. cant remember exactly which. dont know how HK does theirs.

a big downside is horrid trigger pulls: the multiple sear thing gives you 3 different trigger pulls to fight your way through. very spongy, very annoying.

IMO that is the worst part of 3rd burst

onwards and upwards!

[akmarksman]

Thanks for the replies. More questions on my part....

So is the AK-47 superior in firepower (not talking about accuracy here) than the M16?

Mechanically, what is it that makes it possible for the AK-47 to have a fully auto? Is it more expensive to make a fully auto rifle than a 3-round burst?

Why do most armies in the world issue 3-round burst guns as standard issue and not fully-auto?

-Thanks

You can have a nuclear tipped .50..but if you don't AIM..all the power in the world doesn't mean squat. Whereas your opponent who happened to sight in on you..using a .22LR can incapcitate you.