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Posted: 5/25/2010 7:22:59 PM EDT
| I understand the operation of an AR-15. I have not (knowingly) experienced bolt bounce, but would like to know a bit more about it. What are the signs of bolt bounce and is this something you can always feel. |
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Same concept of running down the hallway and hitting the door/wall at the end, you bounce back. Now add weight behind you (Buffer) and it takes out the bounce. I've never heard of a rifle/carbine having any bolt bounce with the proper buffer installed.
ETA: Come to think of it, I've never heard or seen it with any buffer installed. |
| You won't ever "feel" it. This condition is why our buffers have sliding weights inside. When the mass of the sliding weight is resonant with the rebound of the carrier as it trys to bounce off of the barrel extension, the forces will cancel each other, thereby keeping the carrier against the extension. When the bolt carrier bounces, misfires can occur during full auto fire because the carrier is back a bit when the hammer strikes the retracted firing pin. Generally, the carrier will not rebound enough to unlock the bolt, so you won't experience an out-of-battery event. The effects of carrier bounce are usually not apparent during semi auto fire because you can't pull the trigger fast enough to experience the effect. |
Hot damb that was a good answer.
Will this cause visible/premature wear on the bolt Quoted:
You won't ever "feel" it. This condition is why our buffers have sliding weights inside. When the mass of the sliding weight is resonant with the rebound of the carrier as it trys to bounce off of the barrel extension, the forces will cancel each other, thereby keeping the carrier against the extension. When the bolt carrier bounces, misfires can occur during full auto fire because the carrier is back a bit when the hammer strikes the retracted firing pin. Generally, the carrier will not rebound enough to unlock the bolt, so you won't experience an out-of-battery event. The effects of carrier bounce are usually not apparent during semi auto fire because you can't pull the trigger fast enough to experience the effect. |
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Will this cause visible/premature wear on the bolt
No. Why would it? Technically it isn't the bolt that is bouncing but the bolt carrier. I recently had a problem with this running a bufferless system. The carrier would sit back too far and absorb energy from the hammer which caused light strikes. I ended up having to engineer an anti-bounce weight into the back of the carrier. |
Just asking, you never know until you ask. 
Quoted:
Will this cause visible/premature wear on the bolt
No. Why would it? Technically it isn't the bolt that is bouncing but the bolt carrier. I recently had a problem with this running a bufferless system. The carrier would sit back too far and absorb energy from the hammer which caused light strikes. I ended up having to engineer an anti-bounce weight into the back of the carrier. |
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Are you shooting full auto? Just wondering why it would be a problem otherwise.
Bolt bounce explanation in this thread: http://www.ar15.com/FORUMS/topic.html?b=3&f=15&t=481049 |
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Quoted:
Will this cause visible/premature wear on the bolt
No. Why would it? Technically it isn't the bolt that is bouncing but the bolt carrier. I recently had a problem with this running a bufferless system. The carrier would sit back too far and absorb energy from the hammer which caused light strikes. I ended up having to engineer an anti-bounce weight into the back of the carrier. It is not a light strike. It is more like a restricted strike as the collar is hitting the carrier and preventing a full strike. It is related to the mechanism/system on the bolt tail that keeps it from firing out of battery. This is a poor explanation. If you look at a older non shrouded BCA you can see easily what to what I am referring. |
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Quoted:
Hot damb that was a good answer.
Will this cause visible/premature wear on the bolt Quoted:
You won't ever "feel" it. This condition is why our buffers have sliding weights inside. When the mass of the sliding weight is resonant with the rebound of the carrier as it trys to bounce off of the barrel extension, the forces will cancel each other, thereby keeping the carrier against the extension. When the bolt carrier bounces, misfires can occur during full auto fire because the carrier is back a bit when the hammer strikes the retracted firing pin. Generally, the carrier will not rebound enough to unlock the bolt, so you won't experience an out-of-battery event. The effects of carrier bounce are usually not apparent during semi auto fire because you can't pull the trigger fast enough to experience the effect. Nope. will cause no unusual wear on the bolt or carrier. |
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I have experienced this.
I put a hbar 16" upper on a lower that had a regular 16" upper before. That upper functioned fine for well opver 1K rounds. I used the Same buffer(spikes T2) & spring, new BCG. Only on rapid fire would I get a click no bang. Light primer strikes. I had to add a H2 buffer to that lower & then I never had a problem again. |
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Watch the following video. Around the 30 second mark they show an M16 firing a 3 shot burst. Watch the carrier just as it closes and you can see it bounce back slightly each time.
http://www.youtube.com/watch?v=vozrLZclXfg |
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Quoted:
Watch the following video. Around the 30 second mark they show an M16 firing a 3 shot burst. Watch the carrier just as it closes and you can see it bounce back slightly each time. http://www.youtube.com/watch?v=vozrLZclXfg I've posted that video before but couldn't find it last night 
BTW the reason there is a "buffer", why there are moving weights inside the buffer, is so that when the bolt closes the moving weights apply a long-duration forward push to help hold the BC closed and prevent or reduce bolt bounce. By the same mechanism they tend to hold the BC at the back of the travel just slightly which gives the ammo in the magazine more time to rise and settle at the correct feed position. |
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No, just looking to learn about the topic.
Quoted:
Are you shooting full auto? Just wondering why it would be a problem otherwise. Bolt bounce explanation in this thread: http://www.ar15.com/FORUMS/topic.html?b=3&f=15&t=481049 |
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Quoted:
In regards to Spikes ST-T2 buffer, "Each buffer is filled with HDTP "High Density Tungsten Powder" so there is No reciprocating weights inside" I asume the powder gives a more fluid shift in weight then. You get very little buffering effect with powder or shot type weights. The progression of weights and the rubber washers that are in regular buffers is what provides the longer duration "push". |
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