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Posted: 1/15/2010 4:27:47 AM EDT
I can understand how full auto works - hold the trigger and the gun keep firing.  But, what is going on mechanically, in guns that allow for a 3 round burst?  What is enabling the 3 round count and cut off when it gets to that point even though the trigger may still be depressed?  Just asking out of curiosity.  Seems like some interesting engineering.
Link Posted: 1/15/2010 4:34:53 AM EDT
[#1]
There are other websites that explain this. Would be suspicious with BATFE if they saw us explaining this here.
Link Posted: 1/15/2010 4:35:43 AM EDT
[#2]
Quoted:
There are other websites that explain this. Would be suspicious with BATFE if they saw us explaining this here.


your tin foil is too tight
Link Posted: 1/15/2010 4:36:04 AM EDT
[#3]
There's a ratchet with three notches in it for the burst.  After the third ratchet, it stops.  The trouble is that if you set it to burst and don't fire off a full three-shot burst before you release the trigger, you next "burst" may only be one shot.
Link Posted: 1/15/2010 4:37:05 AM EDT
[#4]



Quoted:


There are other websites that explain this. Would be suspicious with BATFE if they saw us explaining this here.




 




The number of rounds fired in a burst is almost universally determined by a cam mechanism that trips the trigger mechanism for each shot in the burst. Some designs will terminate the burst if the trigger is released before the burst is complete, while others will reset the cam position, so the next burst will fire a full number of rounds. Other designs, like that on the M16A2 rifle, will fire the remaining rounds in the interrupted burst and then stop.






Link Posted: 1/15/2010 4:37:07 AM EDT
[#5]
Yep, easy enough to find on other sources.  

What a lot of people don't know, and maybe is worth mentioning, is that 3-rd burst is NOT a 3-rd burst in most of our weapons.  It is a burst of up to 3 rds, depending on where the cam is.  Time and time again I have to go over that with soldiers who don't understandthe limitations of their burst feature on their issued weapons.  

ETA: Man, I type too slow and was beat to my point
Link Posted: 1/15/2010 4:37:08 AM EDT
[#6]
A wise old sear once told me.
Link Posted: 1/15/2010 4:38:51 AM EDT
[#7]
Quoted:
There are other websites that explain this. Would be suspicious with BATFE if they saw us explaining this here.


There's a 6 toothed gear set up to only rotate backwards with the hammer. Two of the teeth, equally spaced, are deeper than the others. Once the hammer rotates three times, a disconnector with a corresponding tooth will sink into the deeper tooth of the 6 toothed gear, meaning the disconnector rotates forward more, and catches the hammer instead of letting it fall. Then, you release the trigger just like with a semi-auto, the disconnector lets go and the trigger holds the hammer, ready to be fired again.
Link Posted: 1/15/2010 4:40:44 AM EDT
[#8]
See the extra doodads?

Link Posted: 1/15/2010 4:46:05 AM EDT
[#9]



Quoted:


A wise old sear once told me.







 
Link Posted: 1/15/2010 4:50:19 AM EDT
[#10]
Number 2 in the above pic is a cam that rotates one notch every shot.  after the third shot it rotates to a notch that has larger and it stops the action by engaging the disconnector.
Link Posted: 1/15/2010 4:51:58 AM EDT
[#11]
This should answer your question.

http://www.ar15.com/forums/topic.html?b=12&f=2&t=79
Link Posted: 1/15/2010 4:56:41 AM EDT
[#12]
Quoted:
There are other websites that explain this. Would be suspicious with BATFE if they saw us explaining this here.


might as well fire off some other keywords for the BATF Google search machine....

SUPPRESSORS, How to?

Gun Show Loophole - I'll meet you in the parking lot with cash yo!

Cop Killer Bullets - which one is right for my Lorcin?




Link Posted: 1/15/2010 5:01:08 AM EDT
[#13]



Quoted:


There are other websites that explain this. Would be suspicious with BATFE if they saw us explaining this here.


Yes, because all machine guns and their related parts are definitely illegal. No one on ARFCOM owns a pre 1986 machine gun, never has and never will.



[/sarcasm]



 
Link Posted: 1/15/2010 5:04:03 AM EDT
[#14]
Now my question is how does the clutch spring work?  

Also there is no law makeing it illeagle to learn how something works.  The knowledge isn't illegal the act of converting illegaly is where the problem come in.
Link Posted: 1/15/2010 5:08:54 AM EDT
[#15]



Quoted:


This should answer your question.



http://www.ar15.com/forums/topic.html?b=12&f=2&t=79


That is the clearest explanation I have ever read. Thanks for it.



 
Link Posted: 1/15/2010 5:12:05 AM EDT
[#16]
Quoted:
Quoted:
There are other websites that explain this. Would be suspicious with BATFE if they saw us explaining this here.


might as well fire off some other keywords for the BATF Google search machine....

SUPPRESSORS, How to?

Gun Show Loophole - I'll meet you in the parking lot with cash yo!

Cop Killer Bullets - which one is right for my Lorcin?






How do I convert my suppressor to full-auto , make it armor piercing and undetectable to airport scanners ?
Link Posted: 1/15/2010 5:16:23 AM EDT
[#17]
Quoted:
There's a ratchet with three notches in it for the burst.  After the third ratchet, it stops.  The trouble is that if you set it to burst and don't fire off a full three-shot burst before you release the trigger, you next "burst" may only be one shot.


i did not know that

Link Posted: 1/15/2010 5:26:51 AM EDT
[#18]
Burst is a big POS, in my opinion.

We had no problem firing short bursts from our M16A1s when needed, it doesn't take a rocket scientist to fire a burst from full auto mode.
With a clip-on bipod, you could do a reasonable amount of auto if needed in a pinch, for an FPL of fire  for example, if your squad belt fed weapon was down, or more were needed.

With the M16A2 "Burst" mode sometimes you would get 3 rounds, sometime 2. I found it a bit ridiculous.


The Army needd to go back to safe-semi-auto, or do like the Germans and do safe-semi-burst-auto.
Either that or go back to semi only. Burst is useless in my opinion.

But then I am a heretic anyway because I thought that with the exception of the heavier barrel and 1-7 ratio, square FSP, and improved furniture, the M16A1 was better than the A2 in all other respects. The sights were more suited to combat, the stock length was better and the firing modes were common sense.

Call me Old School.
Link Posted: 1/15/2010 5:32:25 AM EDT
[#19]
Quoted:
Quoted:
Quoted:
There are other websites that explain this. Would be suspicious with BATFE if they saw us explaining this here.


might as well fire off some other keywords for the BATF Google search machine....

SUPPRESSORS, How to?

Gun Show Loophole - I'll meet you in the parking lot with cash yo!

Cop Killer Bullets - which one is right for my Lorcin?






How do I convert my suppressor to full-auto , make it armor piercing and undetectable to airport scanners ?



File down the firing pin. Place in Jello mold to fool airport scanners.

Link Posted: 1/15/2010 5:54:43 AM EDT
[#20]
Quoted:
Burst is a big POS, in my opinion.

We had no problem firing short bursts from our M16A1s when needed, it doesn't take a rocket scientist to fire a burst from full auto mode.
With a clip-on bipod, you could do a reasonable amount of auto if needed in a pinch, for an FPL of fire  for example, if your squad belt fed weapon was down, or more were needed.

With the M16A2 "Burst" mode sometimes you would get 3 rounds, sometime 2. I found it a bit ridiculous.


The Army needd to go back to safe-semi-auto, or do like the Germans and do safe-semi-burst-auto.
Either that or go back to semi only. Burst is useless in my opinion.

But then I am a heretic anyway because I thought that with the exception of the heavier barrel and 1-7 ratio, square FSP, and improved furniture, the M16A1 was better than the A2 in all other respects. The sights were more suited to combat, the stock length was better and the firing modes were common sense.

Call me Old School.


A2 was designed for camp perry ...
Link Posted: 1/15/2010 6:02:05 AM EDT
[#21]
now should we discuss why 3 rnd burst is even an option?   why add extra potential points of failure? Why cant people just remove their booger hook off the trigger when they want to stop firing?
Link Posted: 1/15/2010 6:15:39 AM EDT
[#22]
Quoted:
now should we discuss why 3 rnd burst is even an option?   why add extra potential points of failure? Why cant people just remove their booger hook off the trigger when they want to stop firing?


Because most of the mil doesn't train to a high enough standard.  

Most Americans try to solve most problems, from IEDs to speeding to high cholesterol to ANYTHING, with gizmos and machines and new stuff rather than people and their actions.  
Link Posted: 1/15/2010 6:17:21 AM EDT
[#23]
Quoted:
now should we discuss why 3 rnd burst is even an option?   why add extra potential points of failure? Why cant people just remove their booger hook off the trigger when they want to stop firing?


I read somewhere it was an attempt to keep Soldiers from wasting ammo.

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