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Posted: 3/30/2012 5:17:51 AM EDT
So it is actually bolt carrier bounce.  I got that.    But, what are some of the cures for it?

I understand the basic concept and causes.    One of my 16" ARs is experiencing it n3ow.   It is a carbine gas system.   It uses a semi bolt.     Generally, it works great and feeds reliably.   However, if I really get on it and dump a mag  of 20 to 30 rounds  in 2 to 3 seconds, I will sometimes "get nothing"/(lite hammer strikes).   Some ammo makes it more noticeable than others.   That difference is the result of  the difference in the pressures and gas.  

The concept of the hydraulic buffers seems good.    But, I never needed one on my  M16 or M4.   So, I guess a hydraulic buffer does not seem natural to me.   Also,  after an episode of "Sons of Guns" in which a hot topic was the need for them to use a hydraulic buffer, several on here have posted sarcastic comments regarding the hydraulic buffers.  

I don't know much about adjustable gas tubes either.   Maybe that is something to consider.

In any case, tell me about how you have overcome over gassing.
Link Posted: 3/30/2012 5:20:57 AM EDT
[#1]



Quoted:






In any case, tell me about how you have overcome over gassing.





I usually just take a Bean-o and wait it out...



 
Link Posted: 3/30/2012 5:21:00 AM EDT
[#2]
Quoted: In any case, tell me about how you have overcome over gassing.



no beans in chili
Link Posted: 3/30/2012 5:21:43 AM EDT
[#3]



ETA:

Damn, you guys are fast.  By the time I read the thread, and went to google images and found this one...I had two posts in front of me on the same line of thinking.
Link Posted: 3/30/2012 5:26:33 AM EDT
[#4]
Quoted:
So it is actually bolt carrier bounce.  I got that.    But, what are some of the cures for it?

I understand the basic concept and causes.    One of my 16" ARs is experiencing it n3ow.   It is a carbine gas system.   It uses a semi bolt.     Generally, it works great and feeds reliably.   However, if I really get on it and dump a mag  of 20 to 30 rounds  in 2 to 3 seconds, I will sometimes "get nothing"/(lite hammer strikes).   Some ammo makes it more noticeable than others.   That difference is the result of  the difference in the pressures and gas.  

The concept of the hydraulic buffers seems good.    But, I never needed one on my  M16 or M4.   So, I guess a hydraulic buffer does not seem natural to me.   Also,  after an episode of "Sons of Guns" in which a hot topic was the need for them to use a hydraulic buffer, several on here have posted sarcastic comments regarding the hydraulic buffers.  

I don't know much about adjustable gas tubes either.   Maybe that is something to consider.

In any case, tell me about how you have overcome over gassing.


Quoted for posterity. Are you talking about a full auto weapon? I sure hope so because otherwise I'm going to call BS. I am very proficient with an AR and we do a half half drill where in one stage it's 10 shots on target with a par time of 2.5 seconds. My best is 2.1 seconds or 4.7 rnds/sec. You're claiming 10 rnds/sec which in my mind is not possible in semi auto.



Link Posted: 3/30/2012 5:30:56 AM EDT
[#5]
Quoted:
You're claiming 10 rnds/sec which in my mind is not possible in semi auto.


I concur.

BCM - HSP Combat Effectiveness Drill

15rds, 1.99 seconds... and as many leg-humpers will tell you, if Haley can't do it then it can't be done.
Link Posted: 3/30/2012 5:34:56 AM EDT
[#6]
Quoted:
So it is actually bolt carrier bounce.  I got that.    But, what are some of the cures for it?

I understand the basic concept and causes.    One of my 16" ARs is experiencing it n3ow.   It is a carbine gas system.   It uses a semi bolt.     Generally, it works great and feeds reliably.   However, if I really get on it and dump a mag  of 20 to 30 rounds  in 2 to 3 seconds, I will sometimes "get nothing"/(lite hammer strikes).   Some ammo makes it more noticeable than others.   That difference is the result of  the difference in the pressures and gas.  

The concept of the hydraulic buffers seems good.    But, I never needed one on my  M16 or M4.   So, I guess a hydraulic buffer does not seem natural to me.   Also,  after an episode of "Sons of Guns" in which a hot topic was the need for them to use a hydraulic buffer, several on here have posted sarcastic comments regarding the hydraulic buffers.  

I don't know much about adjustable gas tubes either.   Maybe that is something to consider.

In any case, tell me about how you have overcome over gassing.


Heavier buffers or stronger buffer springs, or a combo of the two. Get a Tubbs flat wire spring and try that out. If that doesn't fix it, step up to an
H1 or H2 buffer.

-ZA
Link Posted: 3/30/2012 5:38:07 AM EDT
[#7]
Link Posted: 3/30/2012 5:38:22 AM EDT
[#8]
Quoted:
So it is actually bolt carrier bounce.  I got that.    But, what are some of the cures for it?

I understand the basic concept and causes.    One of my 16" ARs is experiencing it n3ow.   It is a carbine gas system.   It uses a semi bolt.     Generally, it works great and feeds reliably.   However, if I really get on it and dump a mag  of 20 to 30 rounds  in 2 to 3 seconds, I will sometimes "get nothing"/(lite hammer strikes).   Some ammo makes it more noticeable than others.   That difference is the result of  the difference in the pressures and gas.  

The concept of the hydraulic buffers seems good.    But, I never needed one on my  M16 or M4.   So, I guess a hydraulic buffer does not seem natural to me.   Also,  after an episode of "Sons of Guns" in which a hot topic was the need for them to use a hydraulic buffer, several on here have posted sarcastic comments regarding the hydraulic buffers.  

I don't know much about adjustable gas tubes either.   Maybe that is something to consider.

In any case, tell me about how you have overcome over gassing.


I've not had those problems in a semi-auto 16" AR.

I've had UNDER gassing problems, but not over gassing.

Hyrdolic buffers are a waste of time in a semi-auto much like anti-walk/rotation pins. neat idea but more for the gear queer crowd with semi-autos. Those running RDIA, LL, RR, etc those make alot of sense.


1. Try a 9mm buffer and a new buffer spring.
2. Then try a new M16 CARRIER.
3. Then try an adjustable gas setting.


I've listed the above in the order of cheapest and easiest to most expensive/more difficult to do.
The adjustable gas blocks are more for folks using SBR's where the dwell time needs to be tweaked, but in your instance it may become necessary as your gas port may have been drilled out to large if this was a used barrel and someone bubba-'ed it up before you owned it. This is all guessing as I don't know diddily about your upper.

Link Posted: 3/30/2012 5:45:05 AM EDT
[#9]
Quoted:
Quoted:
You're claiming 10 rnds/sec which in my mind is not possible in semi auto.


I concur.

BCM - HSP Combat Effectiveness Drill

15rds, 1.99 seconds... and as many leg-humpers will tell you, if Haley can't do it then it can't be done.


That's pretty freaking fast. For the record though, my time is from a high ready and at 15 yards

Link Posted: 3/30/2012 5:53:11 AM EDT
[#10]
Quoted:
Quoted:
So it is actually bolt carrier bounce.  I got that.    But, what are some of the cures for it?

I understand the basic concept and causes.    One of my 16" ARs is experiencing it n3ow.   It is a carbine gas system.   It uses a semi bolt.     Generally, it works great and feeds reliably.   However, if I really get on it and dump a mag  of 20 to 30 rounds  in 2 to 3 seconds, I will sometimes "get nothing"/(lite hammer strikes).   Some ammo makes it more noticeable than others.   That difference is the result of  the difference in the pressures and gas.  

The concept of the hydraulic buffers seems good.    But, I never needed one on my  M16 or M4.   So, I guess a hydraulic buffer does not seem natural to me.   Also,  after an episode of "Sons of Guns" in which a hot topic was the need for them to use a hydraulic buffer, several on here have posted sarcastic comments regarding the hydraulic buffers.  

I don't know much about adjustable gas tubes either.   Maybe that is something to consider.

In any case, tell me about how you have overcome over gassing.


Quoted for posterity. Are you talking about a full auto weapon? I sure hope so because otherwise I'm going to call BS. I am very proficient with an AR and we do a half half drill where in one stage it's 10 shots on target with a par time of 2.5 seconds. My best is 2.1 seconds or 4.7 rnds/sec. You're claiming 10 rnds/sec which in my mind is not possible in semi auto.







It is semi.    No BS.    Email me at [email protected] if you would like to post the video for me.

Link Posted: 3/30/2012 5:57:06 AM EDT
[#11]
Purchase a barrel with the correct size gas port.
Link Posted: 3/30/2012 5:57:57 AM EDT
[#12]
Assuming this light primer strike issue only happens when you are firing the gun extremely fast, I would do the below starting at the top and go down the list until the problem disappears:

1. replace buffer spring with mil-spec carbine spring
2. install an "H" buffer
3. install mil-spec gas tube (EDIT - thanks for reminder from Daytona955i)
4. install a mil-spec M16 bolt carrier
5. replace barrel with mil-spec barrel

If you get light primer strikes occasionally when firing slow, I would first ensure the firing pin and bolt are clean and oiled, and install a new mil-spec hammer spring before doing anything in the above list.

If your gun is mil-spec then there is no way it is going to be having the problem that you are seeing unless you are capable of pulling the trigger so fast on followup shots that you are dropping the hammer before the bolt has time to close. I seriously doubt you are capable of pulling a trigger that fast.
Link Posted: 3/30/2012 5:58:03 AM EDT
[#13]
Quoted:
Quoted:
Quoted:
So it is actually bolt carrier bounce.  I got that.    But, what are some of the cures for it?

I understand the basic concept and causes.    One of my 16" ARs is experiencing it n3ow.   It is a carbine gas system.   It uses a semi bolt.     Generally, it works great and feeds reliably.   However, if I really get on it and dump a mag  of 20 to 30 rounds  in 2 to 3 seconds, I will sometimes "get nothing"/(lite hammer strikes).   Some ammo makes it more noticeable than others.   That difference is the result of  the difference in the pressures and gas.  

The concept of the hydraulic buffers seems good.    But, I never needed one on my  M16 or M4.   So, I guess a hydraulic buffer does not seem natural to me.   Also,  after an episode of "Sons of Guns" in which a hot topic was the need for them to use a hydraulic buffer, several on here have posted sarcastic comments regarding the hydraulic buffers.  

I don't know much about adjustable gas tubes either.   Maybe that is something to consider.

In any case, tell me about how you have overcome over gassing.


Quoted for posterity. Are you talking about a full auto weapon? I sure hope so because otherwise I'm going to call BS. I am very proficient with an AR and we do a half half drill where in one stage it's 10 shots on target with a par time of 2.5 seconds. My best is 2.1 seconds or 4.7 rnds/sec. You're claiming 10 rnds/sec which in my mind is not possible in semi auto.







It is semi.    No BS.    Email me at [email protected] if you would like to post the video for me.



If you can do that god bless you. Email me the video at [email protected] and I will post it up for you.

Link Posted: 3/30/2012 5:58:49 AM EDT
[#14]
Quoted:
Quoted:
You're claiming 10 rnds/sec which in my mind is not possible in semi auto.


I concur.

BCM - HSP Combat Effectiveness Drill

15rds, 1.99 seconds... and as many leg-humpers will tell you, if Haley can't do it then it can't be done.


It is not hard to do.    Email me at yahoo if you want to post my video on here.  




Link Posted: 3/30/2012 6:00:18 AM EDT
[#15]
Please no gun talk.  This is GD.  Guns are the ick.
Link Posted: 3/30/2012 6:04:09 AM EDT
[#16]





Quoted:



Assuming this light primer strike issue only happens when you are firing the gun extremely fast, I would do the below starting at the top and go down the list until the problem disappears:





1. replace buffer spring with mil-spec carbine spring


2. install an "H" buffer


3. install a mil-spec M16 bolt carrier


4. replace barrel with mil-spec barrel





If you get light primer strikes occasionally when firing slow, I would first ensure the firing pin and bolt are clean and oiled, and install a new mil-spec hammer spring before doing anything in the above list.





If your gun is mil-spec then there is no way it is going to be having the problem that you are seeing unless you are capable of pulling the trigger so fast on followup shots that you are dropping the hammer before the bolt has time to close.



This is very good advice. I'd also check to make sure your gas tube/gas port is within spec.


 
Link Posted: 3/30/2012 6:11:18 AM EDT
[#17]
Thanks.   I'm at work  and posting from my phone.    I'll send the emails after my meeting.

Much love to you.
Link Posted: 3/30/2012 7:01:37 AM EDT
[#18]
Semi Bolt? Are you talking about the Bolt Carrier?



What buffer are you currently using?

How many rounds do you have through your current recoil spring?



If you are using 5.56 spec ammo (Mk262, MK318, M-193, M-855, etc...) then step up to the H2 buffer. Also try a new spring.



Springs and buffers are cheap.



 
Link Posted: 3/30/2012 7:23:57 AM EDT
[#19]
Quoted:
Quoted:
Quoted:
Quoted:
So it is actually bolt carrier bounce.  I got that.    But, what are some of the cures for it?

I understand the basic concept and causes.    One of my 16" ARs is experiencing it n3ow.   It is a carbine gas system.   It uses a semi bolt.     Generally, it works great and feeds reliably.   However, if I really get on it and dump a mag  of 20 to 30 rounds  in 2 to 3 seconds, I will sometimes "get nothing"/(lite hammer strikes).   Some ammo makes it more noticeable than others.   That difference is the result of  the difference in the pressures and gas.  

The concept of the hydraulic buffers seems good.    But, I never needed one on my  M16 or M4.   So, I guess a hydraulic buffer does not seem natural to me.   Also,  after an episode of "Sons of Guns" in which a hot topic was the need for them to use a hydraulic buffer, several on here have posted sarcastic comments regarding the hydraulic buffers.  

I don't know much about adjustable gas tubes either.   Maybe that is something to consider.

In any case, tell me about how you have overcome over gassing.


Quoted for posterity. Are you talking about a full auto weapon? I sure hope so because otherwise I'm going to call BS. I am very proficient with an AR and we do a half half drill where in one stage it's 10 shots on target with a par time of 2.5 seconds. My best is 2.1 seconds or 4.7 rnds/sec. You're claiming 10 rnds/sec which in my mind is not possible in semi auto.




It is semi.    No BS.    Email me at [email protected] if you would like to post the video for me.



If you can do that god bless you. Email me the video at [email protected] and I will post it up for you.



[email protected]

That right?    I have several emails waiting to go out from my gmail account from my tablet.  

Posting from work, on my phone and tablet.

Link Posted: 3/30/2012 7:25:05 AM EDT
[#20]
Double tap... too fast on that trigger again.
Link Posted: 3/30/2012 7:32:13 AM EDT
[#21]
Well, my suggestion is that if it only happens during mag dumps, then you should stop doing mag dumps.

Your wallet will thank you.
Link Posted: 3/30/2012 7:53:49 AM EDT
[#22]
Thanks everyone.    Everything was pretty much as expected.   The jokes, the BS challenges, and especially the suggestions were inline with my expectations.    I appreciate your time in going over this with me.

Much love.
Link Posted: 3/30/2012 8:00:35 AM EDT
[#23]



Quoted:


Thanks everyone.    Everything was pretty much as expected.   The jokes, the BS challenges, and especially the suggestions were inline with my expectations.    I appreciate your time in going over this with me.



Much love.


You have some answers already, and it's really hard to believe you can pull off 10 rds/s semi. Post a video to shut everyone up?





 
Link Posted: 3/30/2012 8:10:15 AM EDT
[#24]
spikes ST-T2 buffer = fix for bounce...



i think its 25 or 35$



look on utube for vids of it working

Link Posted: 3/30/2012 8:16:19 AM EDT
[#25]



Quoted:


Thanks everyone.    Everything was pretty much as expected.   The jokes, the BS challenges, and especially the suggestions were inline with my expectations.    I appreciate your time in going over this with me.



Much love.


Hey, you're the one who came to GD expecting straight answers. Surprisingly, you even got some.



Your video does not seem to be loading.



 
Link Posted: 3/30/2012 8:18:32 AM EDT
[#26]
Quoted:

Quoted:
Thanks everyone.    Everything was pretty much as expected.   The jokes, the BS challenges, and especially the suggestions were inline with my expectations.    I appreciate your time in going over this with me.

Much love.

You have some answers already, and it's really hard to believe you can pull off 10 rds/s semi. Post a video to shut everyone up?

 


I do understand .      It is done through "bumpimg".    I can do from the shoulder without a specialized stock with some of my ARs.    But, I also do have one of those SSAR-15 stocks too.     The specialized stocks do aid in control while bumping.  

Thebomber is trying to help me out .      I do not know if my video will be in an useable format .      If anyone has to see what is like, right now, just go to youtube and type in SSAR-15.     My 9mm ARs are super fast and do not have the bolt bounce issues either.     On youtube, you can see that the 9mm ARs, being straight blowback, are faster.

Link Posted: 3/30/2012 8:25:12 AM EDT
[#27]
Quoted:

Quoted:
Thanks everyone.    Everything was pretty much as expected.   The jokes, the BS challenges, and especially the suggestions were inline with my expectations.    I appreciate your time in going over this with me.

Much love.

Hey, you're the one who came to GD expecting straight answers. Surprisingly, you even got some.

Your video does not seem to be loading.
 


I'm at work.   Can't use work PC for this sort of stuff.     I am using my phone and tablet.    Also,  I sent my video to "thebomber".    He is trying to help me out.    But, I don't know that the format will be useable for him .    Plus ,    he is busy too.

Oh, I wasn't being sarcastic.
Link Posted: 3/30/2012 8:27:38 AM EDT
[#28]
Quoted:

Quoted:
Thanks everyone.    Everything was pretty much as expected.   The jokes, the BS challenges, and especially the suggestions were inline with my expectations.    I appreciate your time in going over this with me.

Much love.

Hey, you're the one who came to GD expecting straight answers. Surprisingly, you even got some.

Your video does not seem to be loading.
 


He got some answers and shared his much love with us.  We all win.
Link Posted: 3/30/2012 9:09:01 AM EDT
[#29]
Quoted:
Quoted:

Quoted:
Thanks everyone.    Everything was pretty much as expected.   The jokes, the BS challenges, and especially the suggestions were inline with my expectations.    I appreciate your time in going over this with me.

Much love.

You have some answers already, and it's really hard to believe you can pull off 10 rds/s semi. Post a video to shut everyone up?

 


I do understand .      It is done through "bumpimg".    I can do from the shoulder without a specialized stock with some of my ARs.    But, I also do have one of those SSAR-15 stocks too.     The specialized stocks do aid in control while bumping.  

Thebomber is trying to help me out .      I do not know if my video will be in an useable format .      If anyone has to see what is like, right now, just go to youtube and type in SSAR-15.     My 9mm ARs are super fast and do not have the bolt bounce issues either.     On youtube, you can see that the 9mm ARs, being straight blowback, are faster.



If you are doing some sort of bump-firing and you fired a round and then pulled the trigger again after the hammer resets but before the bolt completely closed, then that would result in a light firing pin strike as you described in your OP. This is technically possible if you are able to pull the trigger that fast (about 750 rounds per minute). Full-auto closed bolt weapons including the M16 generally have a full-auto sear that will not let the hammer fall until the bolt is completely closed. The AR15 semi-auto does not have any mechanism to keep the hammer from falling while the bolt is partially open. If you are indeed pulling the trigger too fast to beat the bolt cycle time, then the only way to fix this issue is to slow down on pulling the trigger to slower than the cycle time of the bolt, or figure out a way to speed up the bolt cycle time while also maintaining reliability.
Link Posted: 3/30/2012 9:58:11 AM EDT
[#30]
Quoted:

If you are doing some sort of bump-firing and you fired a round and then pulled the trigger again after the hammer resets but before the bolt completely closed, then that would result in a light firing pin strike as you described in your OP. This is technically possible if you are able to pull the trigger that fast (about 750 rounds per minute). Full-auto closed bolt weapons including the M16 generally have a full-auto sear that will not let the hammer fall until the bolt is completely closed. The AR15 semi-auto does not have any mechanism to keep the hammer from falling while the bolt is partially open. If you are indeed pulling the trigger too fast to beat the bolt cycle time, then the only way to fix this issue is to slow down on pulling the trigger to slower than the cycle time of the bolt, or figure out a way to speed up the bolt cycle time while also maintaining reliability.



That could be.   But, in this case, it is typical bolt bounce.      Actually, the bolt stays locked and the carrier slightly bounces, and as the  hammer releases, the bouncing carrier absorbs some of the hammer's energy.  

It happens more with higher energy rounds which increase the velocity of the BCG.

Also, the 9mm ARs use the same fire control components, cycle much faster, but do not have the same problems.   So, the issue is not in the  trigger/hammer/fire control.  

I am going to add a Tubb's spring, different buffer (like a Colt 9mm buffer ) , and switch to a full auto carrier.    I do think I will play with a hydraulic buffer sometime just for S&Gs .
Link Posted: 3/30/2012 11:27:26 AM EDT
[#31]
Quoted:
Quoted:

If you are doing some sort of bump-firing and you fired a round and then pulled the trigger again after the hammer resets but before the bolt completely closed, then that would result in a light firing pin strike as you described in your OP. This is technically possible if you are able to pull the trigger that fast (about 750 rounds per minute). Full-auto closed bolt weapons including the M16 generally have a full-auto sear that will not let the hammer fall until the bolt is completely closed. The AR15 semi-auto does not have any mechanism to keep the hammer from falling while the bolt is partially open. If you are indeed pulling the trigger too fast to beat the bolt cycle time, then the only way to fix this issue is to slow down on pulling the trigger to slower than the cycle time of the bolt, or figure out a way to speed up the bolt cycle time while also maintaining reliability.



That could be.   But, in this case, it is typical bolt bounce.      Actually, the bolt stays locked and the carrier slightly bounces, and as the  hammer releases, the bouncing carrier absorbs some of the hammer's energy.  

It happens more with higher energy rounds which increase the velocity of the BCG.

Also, the 9mm ARs use the same fire control components, cycle much faster, but do not have the same problems.   So, the issue is not in the  trigger/hammer/fire control.  

I am going to add a Tubb's spring, different buffer (like a Colt 9mm buffer ) , and switch to a full auto carrier.    I do think I will play with a hydraulic buffer sometime just for S&Gs .



How do you know that the hammer is hitting the firing pin after the bolt carrier has bounced back from fully closed vs. the hammer hitting the firing pin when the bolt carrier did not have time to initially close?? How do you know which it is?

I don't know what configuration you are using but ask yourself if the real full-auto weapons made by Colt in the same config have a problem with bolt bounce. Does Colt ship the full-auto version with a hydraulic buffer or a Tubb's spring?
Link Posted: 3/30/2012 11:51:45 AM EDT
[#32]



Quoted:



Quoted:



If you are doing some sort of bump-firing and you fired a round and then pulled the trigger again after the hammer resets but before the bolt completely closed, then that would result in a light firing pin strike as you described in your OP. This is technically possible if you are able to pull the trigger that fast (about 750 rounds per minute). Full-auto closed bolt weapons including the M16 generally have a full-auto sear that will not let the hammer fall until the bolt is completely closed. The AR15 semi-auto does not have any mechanism to keep the hammer from falling while the bolt is partially open. If you are indeed pulling the trigger too fast to beat the bolt cycle time, then the only way to fix this issue is to slow down on pulling the trigger to slower than the cycle time of the bolt, or figure out a way to speed up the bolt cycle time while also maintaining reliability.






That could be.   But, in this case, it is typical bolt bounce.      Actually, the bolt stays locked and the carrier slightly bounces, and as the  hammer releases, the bouncing carrier absorbs some of the hammer's energy.  



It happens more with higher energy rounds which increase the velocity of the BCG.



Also, the 9mm ARs use the same fire control components, cycle much faster, but do not have the same problems.   So, the issue is not in the  trigger/hammer/fire control.  



I am going to add a Tubb's spring, different buffer (like a Colt 9mm buffer ) , and switch to a full auto carrier.    I do think I will play with a hydraulic buffer sometime just for S&Gs .

How can you tell when this only happens when you're firing 10 rounds/sec?





 
Link Posted: 3/30/2012 12:01:11 PM EDT
[#33]



Quoted:



Quoted:




Quoted:

Thanks everyone.    Everything was pretty much as expected.   The jokes, the BS challenges, and especially the suggestions were inline with my expectations.    I appreciate your time in going over this with me.



Much love.


Hey, you're the one who came to GD expecting straight answers. Surprisingly, you even got some.



Your video does not seem to be loading.

 




I'm at work.   Can't use work PC for this sort of stuff.     I am using my phone and tablet.    Also,  I sent my video to "thebomber".    He is trying to help me out.    But, I don't know that the format will be useable for him .    Plus ,    he is busy too.



Oh, I wasn't being sarcastic.

Copy. Sarc-o-meter sent out for calibration.





 
Link Posted: 3/30/2012 12:02:58 PM EDT
[#34]
Quoted:
So it is actually bolt carrier bounce.  I got that.    But, what are some of the cures for it?

I understand the basic concept and causes.    One of my 16" ARs is experiencing it n3ow.   It is a carbine gas system.   It uses a semi bolt.     Generally, it works great and feeds reliably.   However, if I really get on it and dump a mag  of 20 to 30 rounds  in 2 to 3 seconds, I will sometimes "get nothing"/(lite hammer strikes).   Some ammo makes it more noticeable than others.   That difference is the result of  the difference in the pressures and gas.  

The concept of the hydraulic buffers seems good.    But, I never needed one on my  M16 or M4.   So, I guess a hydraulic buffer does not seem natural to me.   Also,  after an episode of "Sons of Guns" in which a hot topic was the need for them to use a hydraulic buffer, several on here have posted sarcastic comments regarding the hydraulic buffers.  

I don't know much about adjustable gas tubes either.   Maybe that is something to consider.

In any case, tell me about how you have overcome over gassing.


Get a full auto carrier...
Link Posted: 3/30/2012 12:03:09 PM EDT
[#35]
Quoted:
In any case, tell me about how you have overcome over gassing.

Quoted:
I am going to add a Tubb's spring, different buffer (like a Colt 9mm buffer ) , and switch to a full auto carrier.    I do think I will play with a hydraulic buffer sometime just for S&Gs .


Rather than messing around with all the "fixes", best option is just replace the barrel and gas system and eliminate the source of the problem.

By the time you buy all those other parts, you'd probably be at about the same cost.
Link Posted: 3/30/2012 8:15:25 PM EDT
[#36]
Quoted:
Semi Bolt? Are you talking about the Bolt Carrier?

What buffer are you currently using?
How many rounds do you have through your current recoil spring?

If you are using 5.56 spec ammo (Mk262, MK318, M-193, M-855, etc...) then step up to the H2 buffer. Also try a new spring.

Springs and buffers are cheap.
 


Yes, I actually meant a semi bolt carrier.   I apologize for the confusion.

I am using the factory carbine buffer.   I have thousands of rounds through the gun and on that recoil buffer spring.

Link Posted: 3/30/2012 8:16:30 PM EDT
[#37]
Quoted:
Well, my suggestion is that if it only happens during mag dumps, then you should stop doing mag dumps.

Your wallet will thank you.


Right, I know.   I just want it to run right and be capable of going that fast, should I decide to do so.
Link Posted: 3/30/2012 8:27:59 PM EDT
[#38]
Quoted:
Get a full auto carrier...


That is certainly one thing I used in the military that is not in this particular carbine.   So, that is something I should change.

Link Posted: 3/30/2012 8:29:52 PM EDT
[#39]
Quoted:
Rather than messing around with all the "fixes", best option is just replace the barrel and gas system and eliminate the source of the problem.

By the time you buy all those other parts, you'd probably be at about the same cost.


That isn't stupid.   But, this isn't about money either.   I would like to keep the factory barrel with this factory rifle.    This is an issue most people would never have found.
Link Posted: 3/30/2012 8:34:51 PM EDT
[#40]
Quoted:
How can you tell when this only happens when you're firing 10 rounds/sec?


Seriously?

That’s easy.   It does not happen at other times.    If I am shooting in a rather traditional manner, there isn’t any issue.    If I am working my finger back and forth as fast as I can, it runs fine.    If I start bumping with certain ammo, it is fine.   However, higher pressure ammo does cause some misfires when rapid fire bumping.







Link Posted: 3/30/2012 8:40:38 PM EDT
[#41]
Had similar problem with a 16" carbine...eventually cracked a bolt too.
Fixed it with a 9mm buffer and an MPI bolt.
Runs fine now.
Link Posted: 3/30/2012 8:49:07 PM EDT
[#42]
I have all of the vids and will host them if necessary but at the moment I am unconvinced it's necessary. I had no idea the OP was talking about "bump firing" . The AR15 FCG is not designed for "bump firing".  As an owner of a FA lower, I am intimately aware of the difference between a semi FCG and a Full auto FCG and the designed in timing between the BCG, sear and hammer. By artificially firing an AR FCG so fast the timing is off. Sure you can try and fix it with a stiffer spring, heavier buffer at al but at the end of the day, it's just a temporary fix.

OP, bump firing is asking the gun to shoot beyond it's design limits so it's no surprise you are having issues. Other posters have given you good advise but kep in mind, you are using the rifle (AR15 FCG) beyond what it was designed to do.
Link Posted: 3/30/2012 9:20:00 PM EDT
[#43]
Oh, there is one thing of note.   Actually, it is a huge note that I failed to mention.    I did switch from a traditional front sight base to a railed front gas block.



I may switch back.    I think, from the carbon build up I found under and around the old front sight base that it allowed a small amount of gas leakage.      I may go back to that traditional front sight base.   The gun does seem to run hotter now with the railed gas block.
Link Posted: 3/30/2012 9:27:17 PM EDT
[#44]
Quoted:
I have all of the vids and will host them if necessary but at the moment I am unconvinced it's necessary. I had no idea the OP was talking about "bump firing" . The AR15 FCG is not designed for "bump firing".  As an owner of a FA lower, I am intimately aware of the difference between a semi FCG and a Full auto FCG and the designed in timing between the BCG, sear and hammer. By artificially firing an AR FCG so fast the timing is off. Sure you can try and fix it with a stiffer spring, heavier buffer at al but at the end of the day, it's just a temporary fix.

OP, bump firing is asking the gun to shoot beyond it's design limits so it's no surprise you are having issues. Other posters have given you good advise but kep in mind, you are using the rifle (AR15 FCG) beyond what it was designed to do.


Yes.   I have run M16s and M4s for 20 years.      Plus, currently, I have many different ARs now.   I know there is a huge difference in what is happening.  

I agree.    As I said, after reading the post, I found the ideas to be reaffirming of my own.

More than anything, one would never see a problem unless they got into bumping and burning different ammo up.    It would not be a concern to most people.   But, I want it be able to run ... fast, if I so desire.



Link Posted: 3/30/2012 9:29:39 PM EDT
[#45]
Quoted:
How do you know that the hammer is hitting the firing pin after the bolt carrier has bounced back from fully closed vs. the hammer hitting the firing pin when the bolt carrier did not have time to initially close?? How do you know which it is?


There is a very good guess in there.    That is something I have had to ask myself.  

This only happens when “bumping” the gun.    It actually happens more when I bump from the shoulder without a bump stock.   Also,   higher pressure rounds cause it to happen more often.  

Also, if one observes the behavior of bolt carrier bounce, they can begin to see which is more likely the case with their own rifle/carbine.    

Quoted:
I don't know what configuration you are using but ask yourself if the real full-auto weapons made by Colt in the same config have a problem with bolt bounce. Does Colt ship the full-auto version with a hydraulic buffer or a Tubb's spring?


Ah!   That is actually a point behind my original post.    As I mentioned, there was an episode of “Sons of Guns” in which they used a hydraulic buffer in a build for the Dept. of Energy (nuke), I think.    Several found that strange.   I know when I watched, I said to myself that it should not be necessary.    Clearly, I get your point.

Nevertheless, the concept of a hydraulic buffer seems intriguing to me.

What stands out to me most are the following:

I have a semi auto carrier and full auto carrier would probably be a good bet.  The weight should make a difference.

I have put thousands rounds through this gun.    A new buffer recoil spring shouldn’t hurt.

I do not care for the factory buffer.   I would like a higher quality piece to replace the factory buffer.

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