AR15.Com Archives
 Help me diagnose my buffer damage
Natedawg  [Member]
11/26/2009 12:51:50 AM
Well I only have a few hundred rounds through my gun and already have buffer damage. Does it look like it is caused by a burr on the bolt or something more serious?

FrankSymptoms  [Team Member]
11/26/2009 1:05:43 AM
Prior ownership by Napoleon_Tannerite?

Seriously... the stuff around the perimeter looks like scarring from the spring, nothing to worry about. The scratches in the middle look like someone used a screwdriver or something to depress the plunger.

If things operate normally, don't worry about it.


ETA Other posters: could this be caused by installing the spring backwards? I don't think it could but maybe ...
Natedawg  [Member]
11/26/2009 1:14:01 AM
Originally Posted By FrankSymptoms:
Prior ownership by Napoleon_Tannerite?

Seriously... the stuff around the perimeter looks like scarring from the spring, nothing to worry about. The scratches in the middle look like someone used a screwdriver or something to depress the plunger.

If things operate normally, don't worry about it.


ETA Other posters: could this be caused by installing the spring backwards? I don't think it could but maybe ...


Nope I bough it brand new. And yes I was just wondering about the perimeter scratches. May be a stupid question but how could it be from the spring if the spring is on the other side?
j3_  [Team Member]
11/26/2009 1:17:25 AM
Mostly likely a burr on the edge of the notched portion at the rear of the carrier.
PartlyCloudy  [Member]
11/26/2009 1:51:37 AM
Here's a similar deal and at least one way to address it. I wouldn't normally link to another forum but I just stumbled onto it yesterday and felt that it might be useful to the OP here. If it's out of line, I'm sure a mod will come along and dress me down.
osprey21  [Life Member]
11/26/2009 5:13:11 AM
Screw TOS.
Grouchy-Hermit  [Team Member]
11/26/2009 6:53:43 AM
Originally Posted By osprey21:
Screw TOS.

TOS?
GreenM4Guy  [Industry Partner]
11/26/2009 7:33:49 AM
Terms of Service?
yekimak  [Team Member]
11/26/2009 7:47:40 AM
Originally Posted By GreenM4Guy:
Terms of Service?


I think it means "the Other Site"

Dano523  [Moderator]
11/26/2009 12:25:52 PM
Originally Posted By Natedawg:
Well I only have a few hundred rounds through my gun and already have buffer damage. Does it look like it is caused by a burr on the bolt or something more serious?

http://farm3.static.flickr.com/2493/4135461564_646eabd778.jpg


Burs on the back of the bolt carrier for the outer mar'g, and a the center scraps are from a bur on the back bottom of the U slot of the carrier when you go to lock the upper receiver down.
Tweak  [Team Member]
12/6/2009 3:43:25 AM
It's impact marks from the buffer retainer that you need to look out for. Those will eventually cause the buffer to bind in the lower receiver extension, if the retainer doesn't break first, and are indicators of much larger problems with the rifle.
Dano523  [Moderator]
12/6/2009 4:20:37 AM
Tweak, Could be wrong, but I an not seeing any retaining pin contact marks on the face of this buffer in the photo he posted.

Number 1 in this photo shows retaining pin contact (and yes on a huge scale),


P.S. Tweak, It's nice to have you back!!!!
1MRBEAN  [Member]
12/6/2009 11:46:11 AM
Originally Posted By Tweak:
It's impact marks from the buffer retainer that you need to look outfor. Those will eventually cause the buffer to bind in the lowerreceiver extension, if the retainer doesn't break first, and areindicators of much larger problems with the rifle.




I agree , the OP's photo shows retainer pin hitting the buffer. The carrier should push the buffer away from the pin just a little bit when the upper is closed. There could be many causes of this. Ive heard its possible the carrier length could be too short or that the retainer pin hole is mislocated. Could the upper be out of spec somewhere where it would cause the carrier to be more forward than normal ?











j3_  [Team Member]
12/6/2009 12:40:21 PM
Originally Posted By 1MRBEAN:
Originally Posted By Tweak:
It's impact marks from the buffer retainer that you need to look outfor. Those will eventually cause the buffer to bind in the lowerreceiver extension, if the retainer doesn't break first, and areindicators of much larger problems with the rifle.




I agree , the OP's photo shows retainer pin hitting the buffer. The carrier should push the buffer away from the pin just a little bit when the upper is closed. There could be many causes of this. Ive heard its possible the carrier length could be too short or that the retainer pin hole is mislocated. Could the upper be out of spec somewhere where it would cause the carrier to be more forward than normal ?













It does not look like marks from the retaining pin. Also what you quoted does not say it is. Only says that is what you need to look out for.

fixit  [Member]
12/6/2009 2:50:56 PM
Dano, that sure looks like #2 arrow in your photo is where the damage is coming from. Is that a rough spot on the carrier or bolt? No way does his retainer pin sit up that
far in his photo.
raygixxer89  [Member]
12/6/2009 3:45:11 PM
If you turn the buffer I'll bet those marks line up exactly to the top of the retainer pin. OP,check to see if the buffer gets pushed into the tube when you slowly close the upper to the lower. if it does then I'll bet that the retaining pin hole was drilled at an angle.
j3_  [Team Member]
12/6/2009 6:07:19 PM
Originally Posted By raygixxer89:
If you turn the buffer I'll bet those marks line up exactly to the top of the retainer pin. OP,check to see if the buffer gets pushed into the tube when you slowly close the upper to the lower. if it does then I'll bet that the retaining pin hole was drilled at an angle.



Of course the retaining pin is drilled on an angle. It is supposed to be. It is drilled on an angle away from the buffer, That is why you see the damaged at the bottom edge of a buffer when it is hitting a retaining pin. The bottom of a retaining pin is sloped and closer to the buffer because of that and because of the angle the hole is drilled on.
The marks in the picture are higher than the pin and are not dents along the bottom edge that would be caused by a buffer hitting the pin.
1MRBEAN  [Member]
12/6/2009 8:20:42 PM
I guess a pic of the back of the carrier would help , there should be some contact marks on it.
1MRBEAN  [Member]
12/6/2009 8:51:41 PM
Originally Posted By j3_:
Originally Posted By 1MRBEAN:
Originally Posted By Tweak:
It's impact marks from the buffer retainer that you need to look outfor. Those will eventually cause the buffer to bind in the lowerreceiver extension, if the retainer doesn't break first, and areindicators of much larger problems with the rifle.




I agree , the OP's photo shows retainer pin hitting the buffer. The carrier should push the buffer away from the pin just a little bit when the upper is closed. There could be many causes of this. Ive heard its possible the carrier length could be too short or that the retainer pin hole is mislocated. Could the upper be out of spec somewhere where it would cause the carrier to be more forward than normal ?













It does not look like marks from the retaining pin. Also what you quoted does not say it is. Only says that is what you need to look out for.





I didnt read that right , thanks for the correction.
Tweak  [Team Member]
12/6/2009 11:37:23 PM

Originally Posted By j3_:
Only says that is what you need to look out for.






I'll try to pop in more often Dano, still getting on my feet.