View Full Version : Is this wear on my buffer normal?
Obscenejesster
05-23-13, 20:10
I just recently noticed some marks on my buffer today while cleaning my rifle. I guess I just really never looked before but it is a relatively new rifle with only 500 rounds through it. It looks like the buffer is hitting the detent but I would think if it was hitting it hard enough, it would have sheared it off.
Are these dings on the buffer normal and should it be hitting the detent like that?
http://i978.photobucket.com/albums/ae266/jrwingate6/20130523_194713_zpsbb181703.jpg (http://s978.photobucket.com/user/jrwingate6/media/20130523_194713_zpsbb181703.jpg.html)
Look at the back end of your bolt carrier. It very likely has some sharp edges that need to be smoothed off.
Completely unrelated: Was that an 80% receiver that you finished? I ask because I've never seen one in-the-white only on the inside.
I'm curious about the above question as well.
And yes, your buffer detent should be the thing keeping your buffer in it's tube.
Obscenejesster
05-23-13, 21:03
Completely unrelated: Was that an 80% receiver that you finished? I ask because I've never seen one in-the-white only on the inside.
Yes, it was a 80 I finished.
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Obscenejesster
05-23-13, 21:06
I'm curious about the above question as well.
And yes, your buffer detent should be the thing keeping your buffer in it's tube.
Yea, I just thought the BCG should be keeping it from slamming up against the detent. I know the detent keeps the buffer in the tube when you detach the upper but I didn't think it would be keeping the buffer in the tube while firing the rifle.
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The rear of the Bolt Carrier should push the buffer face off of the detent. You can watch this happen by closing the receivers and looking at the buffer from the side view.
If when the buffer is pushed back by the carrier the buffer still touches the retainer, then the lower is trash. You can't fix it. The detent hole can't be repositioned, and it'll egg out that hole over time.
It's quite likely that, as mentioned above, it's just the back of the carrier galling the buffer face. That's pretty common.
Obscenejesster
05-24-13, 22:47
The rear of the Bolt Carrier should push the buffer face off of the detent. You can watch this happen by closing the receivers and looking at the buffer from the side view.
If when the buffer is pushed back by the carrier the buffer still touches the retainer, then the lower is trash. You can't fix it. The detent hole can't be repositioned, and it'll egg out that hole over time.
It's quite likely that, as mentioned above, it's just the back of the carrier galling the buffer face. That's pretty common.
I thought about it harder and I think you guys are probably right about the BCG causing the marks. It just looks like there is no way possible the buffer could hit the detent when it's all assembled. Looks like the BCG moves the buffer back ever so slightly. I was also thinking. If this buffer was making contact with the buffer detent everytime I fired the rifle then that little aluminum detent would have sheared on the first few rounds.
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the detent should be steel.
Your lower is slightly out of spec. The hole for the detent retaining pin is most likely a little too far back so that your carrier doesn't make enough contact with the buffer. Your buffer is hitting the detent and causing those marks, it is normal for the carrier to mark the buffer but it's usually more uniform around the entire buffer.
Just take a sharpening stone and smooth out the tail of the carrier around the detent clearance groove.
Knock off the corners and sharp edges.
That will take care of it.
Wormydog1724
05-25-13, 13:10
When you shoot things, contact points do show signs of wear over time. Imagine that.
http://i416.photobucket.com/albums/pp247/wormydog1724/D04B0485-5E67-489B-B76D-B3CBB480DA95-266-00000014B678F6F0_zpsc49af5b1.jpg
Obscenejesster
05-25-13, 15:44
So some people say my lower is out of spec and others say it's just some rough spots on my carrier.
I would imagine if the buffer is slamming into that detent over and over again, it would shear that tiny detent right off. I've seen others shear their detent by just pushing their buffer in with their finger and then letting it go. One would think the force of the rifle cycling is much more and would shear the detent within a few rounds.
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Obscenejesster
05-25-13, 20:16
When you shoot things, contact points do show signs of wear over time. Imagine that.
http://i416.photobucket.com/albums/pp247/wormydog1724/D04B0485-5E67-489B-B76D-B3CBB480DA95-266-00000014B678F6F0_zpsc49af5b1.jpg
How many rounds you think you have through that buffer?
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Use a jp captured buffer and you don't need to use the buffer detent and spring .
Wormydog1724
05-25-13, 21:52
How many rounds you think you have through that buffer?
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Maybe 7000 on that one.
Probably 2000 on this one.
http://i416.photobucket.com/albums/pp247/wormydog1724/B2B5556B-48CC-4A18-86BF-DDB6D74D5C69-708-00000052F940ACA8_zpsf542e0c1.jpg
No need to go to non-standard parts. Simply shoot the rifle more and see if the wear evens out over time. I would say that the more senior members here have all said that its probably the same thing, the carrier marking the buffer face. I could take out an H buffer, paint the face black, and it would be scuffed to hell in a months worth of shooting.
Go out, shoot the gun, and keep an eye on the detent hole. If the detent fails over time, you have an 80% lower that you finished, which you will not be able to return at any time. It's yours, shoot and enjoy. The detent hole ovaling out might then mean a switch to the JP system, but don't rush to spend $150 on something that you need not buy.
When you shoot things, contact points do show signs of wear over time. Imagine that.
http://i416.photobucket.com/albums/pp247/wormydog1724/D04B0485-5E67-489B-B76D-B3CBB480DA95-266-00000014B678F6F0_zpsc49af5b1.jpg
That definitely looks like your buffer is striking the buffer retainer when the Rifle is going through the counter recoil phase. I've seen buffers with many 1000's of rounds that may have a perfect ring worn into the buffer face from the rear of the bolt carrier, but that doesn't have a centered ring and clean edge...only the edge of the buffer face is what's chewed up and it's at the exact same height as your retaining pin. As others have mentioned, if your lower is in spec then the ONLY time your buffer should make contact with that retainer is when you remove the upper and it captures the buffer.
Wormydog1724
05-25-13, 22:09
That definitely looks like your buffer is striking the buffer retainer when the Rifle is going through the counter recoil phase. I've seen buffers with many 1000's of rounds that may have a perfect ring worn into the buffer face from the rear of the bolt carrier, but that doesn't have a centered ring and clean edge...only the edge of the buffer face is what's chewed up and it's at the exact same height as your retaining pin. As others have mentioned, if your lower is in spec then the ONLY time your buffer should make contact with that retainer is when you remove the upper and it captures the buffer.
Approx 3,500 rounds on a Spike's lower, 2,000 rounds on a Noveske chainsaw lower, and 500 rounds on a BCM lower.......... I think its g2g.
Obscenejesster
05-25-13, 22:23
That definitely looks like your buffer is striking the buffer retainer when the Rifle is going through the counter recoil phase. I've seen buffers with many 1000's of rounds that may have a perfect ring worn into the buffer face from the rear of the bolt carrier, but that doesn't have a centered ring and clean edge...only the edge of the buffer face is what's chewed up and it's at the exact same height as your retaining pin. As others have mentioned, if your lower is in spec then the ONLY time your buffer should make contact with that retainer is when you remove the upper and it captures the buffer.
Thats not even my buffer. It's someone else's who also has an out of spec lower. :rolleyes:
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Obscenejesster
05-25-13, 22:29
I just looked at everything and it looks like I need to turn my buffer tube about 1-2 mm clockwise which should bring the buffer further out and keep it from hitting the detent if that's what it is. One more mm should still keep the buffer tube lined up straight.
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Wormydog1724
05-26-13, 09:32
Thats not even my buffer. It's someone else's who also has an out of spec lower. :rolleyes:
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Lol. Man I am confident my Noveske and my BCM are in spec. The wear on those spikes t2 buffers are just part of it. I wouldn't worry about it. I'm certainly not. Like I said, over 9,000 rounds between two buffers (almost 1,000 of them being 6.8 SPC) and still haven't broken anything. Amazing!
That definitely looks like your buffer is striking the buffer retainer when the Rifle is going through the counter recoil phase.
This is the correct answer.
Wow, you guys have some dolled up parts.. Anyhow, I've only seen a nice smooth even edged ring on my buffers. Ron
This is the correct answer.
Really? If you look at the OP's first picture you can see there is no strike damage at the location of the retainer, it is to the sides. Exactly where the bolt carrier rides on the buffer. The bolt carrier is either not relieved properly and has sharp edges or there is something out of spec in the buffer/spring/RE setup.
I'd love to see a close up of the OP's bolt carrier.
Really? If you look at the OP's first picture you can see there is no strike damage at the location of the retainer, it is to the sides. Exactly where the bolt carrier rides on the buffer. The bolt carrier is either not relieved properly and has sharp edges or there is something out of spec in the buffer/spring/RE setup.
I'd love to see a close up of the OP's bolt carrier.
Due to a similar issue I had years ago I would bet that O3Skill was correct, but that said I agree that a picture of the back of the carrier is mandatory to diagnose further. Also I should add that I was told it may be that the lower was out of spec and it was not the case. As well I have never owned a carrier with any sort of burr on the back but apparently they do exist.
Obscenejesster
05-26-13, 14:56
Due to a similar issue I had years ago I would bet that O3Skill was correct, but that said I agree that a picture of the back of the carrier is mandatory to diagnose further. Also I should add that I was told it may be that the lower was out of spec and it was not the case. As well I have never owned a carrier with any sort of burr on the back but apparently they do exist.
What issue did you have years ago?
I have another millimeter or so left to turn the buffer tube. I'm wondering if this will put the buffer a little bit further forward to prevent it from hitting the detent during counter recoil. What do you think?
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What issue did you have years ago?
I have another millimeter or so left to turn the buffer tube. I'm wondering if this will put the buffer a little bit further forward to prevent it from hitting the detent during counter recoil. What do you think?
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In short, no. Only two things will effect the buffers position when it's in the buffer tube, the BCG or the retaining pin. Turning the buffer tube will not change the relationship between the BCG and the retaining pin, that is only affected by the machining of the lower and the overall length of the BCG.
Use the orange search button and the term "bolt carrier burr". Lots of cases of things similar to the OP's.
Obscenejesster
05-26-13, 22:17
Well, I guess there's really nothing I can do if my buffer is hitting the retaining pin due to the lower being out of spec. It still shoots fine and the worst that can happen is the buffer retaining hole egging out over time. At that point, I'm assuming the lower will still be functional and I'll just have to spend $150 on a JP self retaining buffer.
Small price to pay for a lower that's off the books.
Next time I shoot her, I will rotate the buffer and see if it there is new marks exactly where the buffer retaining pin would hit.
Well, I guess there's really nothing I can do if my buffer is hitting the retaining pin due to the lower being out of spec. It still shoots fine and the worst that can happen is the buffer retaining hole egging out over time. At that point, I'm assuming the lower will still be functional and I'll just have to spend $150 on a JP self retaining buffer.
Small price to pay for a lower that's off the books.
Next time I shoot her, I will rotate the buffer and see if it there is new marks exactly where the buffer retaining pin would hit.
You can smooth out the sharp edge on the buffer retainer clearance channel in the back of the carrier, as suggested in posts 2,7,11&25.
If the buffer is hitting the retainer pin ( hint: it's probably not ) you should see all kinds of obvious damage to the lower around the pin ( none was visible in the first pic) and corresponding marks on the buffer pin.
Both the pin and the pin clearance channel in the carrier are at the 6:00 position, so rotating the buffer won't reveal any useful information.
Obscenejesster
05-28-13, 22:41
Tonight, I inspected everything carefully and after taking a closer look, it appears my lower is perfectly fine and the buffer is not slamming into the retaining pin.
First, I looked closely at the wear on the buffer. It is slightly higher than the retaining pin itself.
Second, I spun the pin around to get a look at the side that would have been getting hit with the buffer. No damage at all. I would think there would be a good amount of damage to the pin if the buffer slammed into it 500 times.
Third, I looked at the back of the carrier and like some of you said, the edges of the retaining pin channel were sharp and the phosphate finish was slightly worn off of it. The damage on the buffer matched up with the worn finish on these sharp edges of the channel.
Lastly, I took a flashlight and shined it at the retaining pin as I slid the upper down onto the lower. I physically saw the buffer move back off of the retaining pin as the upper slid into place.
Thanks to everyone for the suggestions. Especially the ones who suggested it was the carrier. To those saying my lower was out of spec. Well thanks for causing me to lose sleep. :D
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