Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
Member Login
Site Notices
9/22/2017 12:11:25 AM
Posted: 3/28/2006 1:06:08 PM EDT
check out the pic its like my retaining pin is tearing into the buffer???

Link Posted: 3/28/2006 1:08:13 PM EDT
a better pic
Link Posted: 3/28/2006 1:14:34 PM EDT
Maybe it's just soft. Get ya a new one at the funshow maybe. Mine is marked up, but it ain't eat on.
Link Posted: 3/28/2006 1:23:52 PM EDT
Have tried the trouble shooting forum? Or maybe this LINK?
Link Posted: 3/28/2006 1:25:23 PM EDT
Link Posted: 3/28/2006 1:28:36 PM EDT
Link Posted: 3/28/2006 1:29:53 PM EDT

Originally Posted By The_Beer_Slayer:
is it just the pic or is your reciever beat to hell around the edges as well?

is there a bur on the bolt carrier?



No kidding! Whiskey Tango Foxtrot?

Link Posted: 3/28/2006 1:31:52 PM EDT
[Last Edit: 3/28/2006 1:34:28 PM EDT by motown_steve]
Is your receiver extension aligned properly? That looks like hell. I wonder if it's scraping when it's moving forward.

ETA - That's probably not it. I've never seen that though.
Link Posted: 3/28/2006 1:34:19 PM EDT
Link Posted: 3/28/2006 1:34:24 PM EDT

Originally Posted By The_Beer_Slayer:
is it just the pic or is your reciever beat to hell around the edges as well?



?



no it just has a fresh coat of CLP the picture made it look weird for some reason.
Link Posted: 3/28/2006 1:35:31 PM EDT
[Last Edit: 3/28/2006 1:39:32 PM EDT by A_Free_Man]
The buffer will never strike the retaining pin when the rifle is assembled. The bolt carrier, even in the full forward postion, keeps that from happening. If the buffer did strike the pin, it would show damage at the very least, and break off in a short time. Note that as you close the upper on your rifle, the rear of the bolt carrier pushes back the buffer.

There is a groove or notch on the bottom of the bolt carrier that clears the buffer retaining pin when the bolt carrier cycles. Where that groove or notch exits the rear of the bolt carrier it often leaves a high spot or burr. This burr repeatedly hitting the buffer is what does the damage your photo shows. The buffer rotates around, and the damage is all around the rim.

Feel the notch on the bottom rear of your bolt carrier... is there a burr? If so, it will chew up the buffer. Use a grinding wheel on a dremel, and dress up that area on the back of the bolt carrier just a little, then use the abrasive rubber polishing wheel and smooth it further. You may want to touch up the spot with a little cold blue. Anyway, that is what chews up the buffers.

BTW, this is VERY common, and I have fixed it on dozens of rifles (including 3 of mine) as per above.
Link Posted: 3/28/2006 1:36:45 PM EDT
[Last Edit: 3/28/2006 1:39:22 PM EDT by DonOhio39]
Your buffer pin is just a tad too far rearward. The buffer should come to rest against the bolt carrier before contacting the pin.

About the only thing you can do is put up with it or machine a relieved edge around the circumference of the buffer face so that it makes proper contact with the carrier.

Don in Ohio

Link Posted: 3/28/2006 1:41:36 PM EDT
If the buffer were hitting the pin while the rifle is assembled and fired, it would quickly break off the pin. I will bet there is no such damage on the retaining pin.

This is from the burr on the back of the bolt carrier.
Link Posted: 3/28/2006 1:45:30 PM EDT
Link Posted: 3/28/2006 1:47:39 PM EDT
My H buffer looks like that and I've never had a problem in about 7000 rounds.
Link Posted: 3/28/2006 1:50:56 PM EDT

Originally Posted By A_Free_Man:
The buffer will never strike the retaining pin when the rifle is assembled. The bolt carrier, even in the full forward postion, keeps that from happening. If the buffer did strike the pin, it would show damage at the very least, and break off in a short time. Note that as you close the upper on your rifle, the rear of the bolt carrier pushes back the buffer.

There is a groove or notch on the bottom of the bolt carrier that clears the buffer retaining pin when the bolt carrier cycles. Where that groove or notch exits the rear of the bolt carrier it often leaves a high spot or burr. This burr repeatedly hitting the buffer is what does the damage your photo shows. The buffer rotates around, and the damage is all around the rim.

Feel the notch on the bottom rear of your bolt carrier... is there a burr? If so, it will chew up the buffer. Use a grinding wheel on a dremel, and dress up that area on the back of the bolt carrier just a little, then use the abrasive rubber polishing wheel and smooth it further. You may want to touch up the spot with a little cold blue. Anyway, that is what chews up the buffers.

BTW, this is VERY common, and I have fixed it on dozens of rifles (including 3 of mine) as per above.



thanks, the back of the buffer does seem a little sharp, maybe that will clear things up.

I am thinking the pin has nothing to do with it???



Link Posted: 3/28/2006 1:51:47 PM EDT

Damage to buffer or buffer retainer

The buffer should not touch the buffer retainer when the rifle is assembled. The buffer only touches the retainer when the upper is removed from the lower. When the rifle is assembled the rear of the carrier pushes the buffer away from the buffer retainer. You should be able to see, hear, and feel this when you close the upper onto the lower. If there are dents in the face of the buffer that correspond to the buffer retainer either the pin hole for the retainer is mis located, the carrier is short, the barrel sits too far forward in the upper, or the upper sits too far forward on the lower. The rear of the carrier should be flush or slightly above the rear of the upper. The rear of the barrel extension should be flush with the inside lip of the upper or recessed no more than ~ 0.012”.

A rough spot on the rear of the carrier most often causes wear on the face of the buffer. The most likely place for the rough spot is at the rear of the key way cut in the bottom of the carrier. Even a small burr on the rear of the carrier will eat away the anodized finish.

The most common cause of damage to the buffer retainer pin is a poorly installed collapsible stock. The lip of the collapsible stock must cover the edge of the retainer pin or the pin will not be retained in its recess.




I've also had a mouse get into my upper receiver via the magwell, he ended up chewing my buffer edge up even worse than in the pics.
Link Posted: 3/28/2006 2:08:41 PM EDT
tag.
Link Posted: 3/28/2006 2:15:46 PM EDT
tag
Link Posted: 3/28/2006 2:16:52 PM EDT
3 threads on the exact same thing... 1 in GD and 2 in AR15


Link Posted: 3/28/2006 2:23:20 PM EDT
[Last Edit: 3/28/2006 2:24:53 PM EDT by LVMIKE]
I have a similar problem, while not as pronounced.

In my case, the hole for the retaining pin was drilled a slight bit too far forward. When I close the weapon, the carrier scrapes fairly hard against the buffer, causing a set of two lines running from the edge to the center. I also had a similar "ring" around the outside of the buffer and it was developing FAST, until I filed the very back edges of the carrier a slight bit. Once the burrs were removed, the wear on my buffer went down dramatically. I did more damage in 500 rounds, then I have in 5000-6000 since I deburred it.

The biggest burr spot was the back, bottom edges, of the channel for the buffer retaining pin. The edge that contacts the carrier is now about a 45 degree angle instead of 90. This helps when I close it and seemed to mellow out the "ring-ing."
Link Posted: 3/28/2006 2:34:34 PM EDT

Originally Posted By numbers:
Have tried the trouble shooting forum? Or maybe this LINK?



Quote from TWEAK in hte second link you provided


Damage to buffer or buffer retainer

The buffer should not touch the buffer retainer when the rifle is assembled. The buffer only touches the retainer when the upper is removed from the lower. When the rifle is assembled the rear of the carrier pushes the buffer away from the buffer retainer. You should be able to see, hear, and feel this when you close the upper onto the lower. If there are dents in the face of the buffer that correspond to the buffer retainer either the pin hole for the retainer is mis located, the carrier is short, the barrel sits too far forward in the upper, or the upper sits too far forward on the lower. The rear of the carrier should be flush or slightly above the rear of the upper. The rear of the barrel extension should be flush with the inside lip of the upper or recessed no more than ~ 0.012”.

A rough spot on the rear of the carrier most often causes wear on the face of the buffer. The most likely place for the rough spot is at the rear of the key way cut in the bottom of the carrier. Even a small burr on the rear of the carrier will eat away the anodized finish.

The most common cause of damage to the buffer retainer pin is a poorly installed collapsible stock. The lip of the collapsible stock must cover the edge of the retainer pin or the pin will not be retained in its recess.




Damn.

The site and its members miss this cat.
Link Posted: 3/28/2006 2:41:29 PM EDT
Link Posted: 3/28/2006 2:55:48 PM EDT
Link Posted: 3/28/2006 4:04:59 PM EDT
Buffer detents being too far to the rear is way more common than most people think when dealing with aftermarket lowers. The buffer should protrude from the tang app .040" or more. When you close the upper you should be able to watch the bolt carrier push the buffer rearward well before the upper and lower are fully closed. That looks like buffer detent dents because they are so close to the periphery and they are slightly angled. The hole for the buffer detent is supposed to be drilled at a 6 degree angle.

rj
Link Posted: 3/28/2006 5:05:51 PM EDT

Originally Posted By numbers:

Damage to buffer or buffer retainer

The buffer should not touch the buffer retainer when the rifle is assembled. The buffer only touches the retainer when the upper is removed from the lower. When the rifle is assembled the rear of the carrier pushes the buffer away from the buffer retainer. You should be able to see, hear, and feel this when you close the upper onto the lower. If there are dents in the face of the buffer that correspond to the buffer retainer either the pin hole for the retainer is mis located, the carrier is short, the barrel sits too far forward in the upper, or the upper sits too far forward on the lower. The rear of the carrier should be flush or slightly above the rear of the upper. The rear of the barrel extension should be flush with the inside lip of the upper or recessed no more than ~ 0.012”.

A rough spot on the rear of the carrier most often causes wear on the face of the buffer. The most likely place for the rough spot is at the rear of the key way cut in the bottom of the carrier. Even a small burr on the rear of the carrier will eat away the anodized finish.

The most common cause of damage to the buffer retainer pin is a poorly installed collapsible stock. The lip of the collapsible stock must cover the edge of the retainer pin or the pin will not be retained in its recess.




I've also had a mouse get into my upper receiver via the magwell, he ended up chewing my buffer edge up even worse than in the pics.



Was his ass chambered in 5.56 or .223? You wouldn't want to hurt the little fella by chambering too big a round in him.
Top Top