Burst fire in the M16

[IZinterrogator]

The Marine Corps got it right by keeping the older safe-fire-auto mode on their version of the M16.

No, they didn't. They have burst only except for the Recon Marines with M4A1s. All M16A2s, M16A4s, and M4s are burst only. The M4A1, used by SOCOM units and the Recon Marines, fires on full auto. No one uses the M16A3, which is the A2 with full auto.

As for how it works, there is a cam with three prongs to the right of the hammer pin hole on the hammer itself. Two will let the hammer fall forward again, the third always stops it. If you fire on burst and only hold the trigger long enough for two rounds to fire, the next trigger pull will only be one shot, even though it is still on burst. The next after that will be three shots, provided you hold it through all three rounds this time.

[rifleer1]

Burst mode is only necessary for covering fire, and then only when you don't have an available squad automatic weapon.

Otherwise semi is the best way to hit what you are shooting at. For CQB we are taught double-taps.

[James K]

Maybe it is just a different way to look at it, but I would not say burst fire is to save ammunition, per se. Since it is difficult for a shooter with an M16 or M4 to get off more than 3 rounds in full auto before the muzzle goes off target, there is not much point in holding down the trigger and firing another 10 or 20 into the air. True two to four round bursts can be achieved by trigger control if enough time and ammunition is dedicated to training for that purpose. The hard fact is that the army (yes, and Marines) just can't spend days with a recruit doing nothing but practicing burst control in full auto fire. The burst fire capability is like an automatic transmission in a car - it is a mechanical means of achieving easily what only a lot of practice could do otherwise.

Stray thought: Most folks who talk a lot about how it should be done, haven't done it.

As to "bubba" FA conversions being dangerous, that is not true with a well made and properly installed DIAS or lightning link. Some people have tried to achieve FA fire by filing sears or some such, either allowing the hammer to follow the bolt down or to fall before the bolt is fully locked. In theory, the rifle cannot fire under those conditions, but such conversions are not the right way to go, and under certain conditions could allow fire out of battery, with almost certain destruction of the weapon.

Jim

[Herbert]

Just to quickly address some things. For starters full auto isn't very difficult to control in the 5.56, you aren't going to be firing into the air after three rounds

From personal experience I found burst to be choppy when trying to do rapid fire when compared to full auto. Full auto has steady recoil that you can to a degree compensate for while burst had a see-saw recoil effect making it more difficult to control.

Secondly it isn't hard to fire off short bursts from a full auto weapon. I almost got kicked off of a M249 range once for firing single shots during qualification on paper targets. Apparently you were supposed to try to use three round burst. Would have had expert except they subtracted ten hits for using single shot. Got called a cheater by those who didn't qualify but I didn't care, I'm a whatever works kinda guy.

As for full auto not being useful it works great during close ambushes and CQB. Firing volume to hit a target at close range is much easier than aiming on semi. It also better long range 300M+. It is extremely difficult to get a precision hit on a moving target at that range without FA, especially since you are only going to have a short window of opportunity to hit before the target takes cover. This would also apply to moving targets in a heavy woodline. Short window of opportunity plus little time to react means FA is handy.

[schwarz_06]

Well of course everyone has their opinions. Mine personally well in a CQB environment, a failure to stop drill will do just fine. But in my experience an M4 can basically be used as a SAW in the right hands. It's all about your stance and how you hold your weapon. Doctrine today for the M16 or the M4 controlled pairs past 15 yards and hammer pairs from 15 and in. and of course one to the face. In the business we call this winning of hearts and minds. I can tell a simple way to change your AR to FA and not cost you a dime or cause permenent change to your weapon but we wont discuss that here. Gunsmithing is quite an art, good luck to you.

[VUPDblue]

I can tell a simple way to change your AR to FA and not cost you a dime or cause permenent change to your weapon but we wont discuss that here. Gunsmithing is quite an art, good luck to you.

That is not what is being discussed here...

[douglasschuckert]

The M16 burst is a cool idea. Devil Dogs (USMC) do have burst on most of their M4 and M16's. The CAM in there is finikey at best. I personally dont like it, but some swear by it... cool idea non-the-less. There really isn't a real defacto answer as to why.. some people say it's because of round placement, some due to cost of ammo, some to the comabt panic factor... yadda yadda... who really knows? Its just 'one of those things'.

The full auto M16 will raise in the air. I've seen it with the newbies using the standard 'weaver' stance (trying to shoot the M16 like your standard hunting rifle). If you use the 'modern isosceles' stance a fairly-practiced person can keep all 30 rounds pretty close together and watching it it looks like the weapon vibrates in the persons hands. (feels like that too... just dont try to sit on it :-)).

[Slateman]

I know its an old thread, but I just got back from Parris Island.

Burst mode rocks

[chaad]

...is on range day when everyone has qualified, there's a couple thousand rounds in mags sitting at the ammo station, and the chow hall closes in an hour. Nobody wants to break down mags, put them back in stripper clips, and recount, so that's when the training schedule changes to "sustained fire drills utilizing rapid magazine exchanges".

My reserve unit just got rid of their A1s this year. They all get sent somewhere in the South to be retooled into A2s. They mill out the "auto" and put a metal tab there for burst. i had an old FN at OBC that had been converted and seen many better days, but ut was still a real shooter. That's probably the most impressive thing about the M16 to me, that I can have one that is a nearly new Colt, and one a rehashed FN, and the sighting on the two was nearly the same (7 up on one, 7 up and one right on the other).

[STLRN]

The hard fact is that the army (yes, and Marines) just can't spend days with a recruit doing nothing but practicing burst control in full auto fire. The burst fire capability is like an automatic transmission in a car - it is a mechanical means of achieving easily what only a lot of practice could do otherwise.

I don't think it is so much we cannot train people to do bursts, that only takes a couple of mags and anyone can manage 2-3 round burst. But under combat stress even guys with unlimited ammo allowances tend to fire much longer than optimal bursts.

[spctim11]

I am no gunsmith but would like one to tell me how a FA weapon such as the M-249 SAW is capable of firing only one round at a time, if it is in complete working order.

[PhilA]

"The trouble is that the Army doesn't really train its soldiers in trigger control"

They did when I went through basic training in the mid-80s. In fact, we were only permitted to go full auto a small handful of times so we could learn how to control our muzzles under sustained fire. All other times we were under strict orders to squeeze the trigger for 3-round maximum bursts. Failures to comply got you 40 pushups at best, or kicked off the range and assigned work detail at worst--and sometimes a good smack upside the head by a drill seargeant.

[Silentarmy]

You don't need to be a gunsmith. You do however need some experience with the M-249! Trigger control. Its not an uzi for hell sake!

[Silentarmy]

Phil
I remember those days! I always wondered what would posess a Drill Instructor to kick the head of an 18 yr old kid with 20 rnds in an automatic weapon! Happened plenty though!!

[MisterPX]

Mechanical burst is cheaper than training folks to use their fingers and discipline.


I don't like the different trigger pulls with the burst cam, nor the having to complete a cycle.

[Nevertoomanyguns]

When I was in the Infantry the M4 and the m16a2 and a3 were all semi and 3 round burts. I now work for Dod police under the navy and our 16a2 are semi and full auto. By the way I like the full auto and regulating the number of rounds by my finger. I do about a 5-10 round burst and can put them all in the head at 50 yards. No joke so don't call me a lier you have to take my word on it.

[3 weelin geezer]

Ok, the m 16 has different parts than th AR of course. One thing it has different is that in burst mode there is a cam/fan shaped part that goes on the right side of the trigger. After its been reset on the third time, 1/2 of the trigger pops forward to catch the hammer. You let go of the trigger and it resets those parts allowing you to 'remove' the hook catching the hammer for another 3 parts. Unfortunately, I didn't get any pictures of the acutal parts when I had to clean a whole mess of those things. If you can get a hold of a 'Cobra' derringer, it has a similar part that controls which firing pin is used and how you get to shoot only one bbl at a time. I don't know if any other derringers work this way so I can't say if any others have this kind of part.

s for the m-16 bolt being different from the ar is that the long hole in the bottom is machined only upto about 1/2 bolt where the disconnector catches it. Since the Ar doesn't (or isn't supposed to have) a disconnector and to insure you don't stick one in there somehow, they machine it further back.

If you are going to buy that tac trigger, hellfire, autoburst crap, save your money. It doesn't behave like you converted your gun because you didn't (hopefully). They just keep your finger against the trigger but you still have to bumpfire it. Its not hard to do that and as soon as you figger out the technique and see how easy it is, you will wonder why all those dunderheads paid $30+ for that little peice of metal/spring that is useless. Well, except to baffle all the people who don't know better but is it worth $30+? I don't think so. I used a paper clip wraped around the trigger guard like the hell fire and many believed it actually did something. :O Its funny to watch them try to fire the "machine gun".

Here is how you do it. http://www.youtube.com/watch?v=PVfwFP_RwTQ

and this:

http://www.youtube.com/watch?v=SzAk-LKF6pE

[spctim11]

You don't need to be a gunsmith. You do however need some experience with the M-249! Trigger control. Its not an uzi for hell sake!

So can it be done with an UZI?

[3 weelin geezer]

Nope. Used an m-60 myself.