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Posted: 4/4/2024 7:27:53 PM EDT
| Ive noticed cam pins seem to get a groove on them easily within 1000 rounds, made me think the one good thing about chromed bcg is the cam pin. I see centurion sells this part standalone. Opinions? |
| I've noticed that cam pins wear to a point then wear stabilizes. Kind of like break in. |
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| $17 seems like an inexpensive upgrade |
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not joeII, I'm Joe
My grandfather was Joe senior, dad Joe Jr, I'm the third.
So my username is joeIII223
Those are three I's not L's
Thanks @whiskerz @Boomer for helping me clear this up.
not joeII, I'm Joe
My grandfather was Joe senior, dad Joe Jr, I'm the third.
So my username is joeIII223
Those are three I's not L's
Thanks @whiskerz @Boomer for helping me clear this up.
| That's most likely due to improper heat treatment or choice of steel (soft end product). I had this issue with my first AR 25 years ago, so I bought several to stock as consumables; I haven't had one wear since. Chrome plating isn't necessary - just good metallurgy with proper cleaning and lubrication. I use MolySlide (a light grease with 60% moly) because this is a high-stress area. |
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Originally Posted By wingsnthings: I've noticed that cam pins wear to a point then wear stabilizes. Kind of like break in. Attached File |
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I never had a cam pin snap on me and I owned AR rifles since about 2007-8 timeframe. As you use the rifle parts will wear and settle in. It is impossible for friction to occur without showing some wearing. Wearing is okay, cracks are not. That's one of the problems when people making cleaning videos is that they're talking about inspecting parts of unusual wearing or cracks or breakage. But reality is what you're seeing is perfectly normal unless there is a crack. Unusual wearing is where it shows deep gouges and it doesn't stop and keeps getting progressively worse after each usage. |
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It’s normal. Install it in the same orientation every time if you can help it, or the other side will “seat” as well making it looser. I have had good results greasing all my cam pins. Better the pin takes some wear vs the bolt or carrier cam slot. Also, carriers like LMT’s e carrier with the steeper cam path eat pins up faster in my experience. |
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Originally Posted By Jnat: It’s normal. Install it in the same orientation every time if you can help it, or the other side will “seat” as well making it looser. I have had good results greasing all my cam pins. Better the pin takes some wear vs the bolt or carrier cam slot. Also, carriers like LMT’s e carrier with the steeper cam path eat pins up faster in my experience. SOTAR nonsense. |
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Originally Posted By OTDR: SOTAR nonsense. Originally Posted By OTDR: Originally Posted By Jnat: It’s normal. Install it in the same orientation every time if you can help it, or the other side will “seat” as well making it looser. I have had good results greasing all my cam pins. Better the pin takes some wear vs the bolt or carrier cam slot. Also, carriers like LMT’s e carrier with the steeper cam path eat pins up faster in my experience. SOTAR nonsense. Like the guy or not… but in doing so, the groove is more or less on one side of the pin vs around the bulk of entire diameter. |
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Originally Posted By casktcrw: When do u know to replace? Should i at least have one for every bcg? What will go faster that or gas rings? I replaced my gas rings often due to wear. It’s never a bad idea to have a space bolt, cam pin, gas rings, bolt ejector and extractor springs and parts, and a fire pin. You know when to replace gas rings when it’s very loose in the bcg. Usually falls out but usually causes brass to behave differently. You know when to replace cam pin or fire pin when it’s actually broke or cracked. However in all my years owning an AR I only ever replace gas rings, ejector springs, extractor spring, and once a chipped fire pin. Never a cam pin but you never know as these things can break but very unlikely and not a super major worry. |
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Chrome lined cam pin after a minimum of 5,000 rounds, probably a bit more but lost track. Attached File Attached File I’ve never had a cam pin break but I suspect the chromed examples are less susceptible based on surface wear. Hardening or inconsistencies who knows, but you can barely feel the wear with a finger nail. If not obvious, I don’t pay attention to orientation. |
https://instagram.com/_odiegreen_?igshid=OGQ5ZDc2ODk2ZA==
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My phosphate and nitride examples have a groove where as I’d say my chrome ones are more of a light surface scratch. I’m not worried about it either way. As stated I’ve never had one break and have extras in the event one does. |
https://instagram.com/_odiegreen_?igshid=OGQ5ZDc2ODk2ZA==
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Originally Posted By -OdieGreen-: My phosphate and nitride examples have a groove where as I’d say my chrome ones are more of a light surface scratch. I’m not worried about it either way. As stated I’ve never had one break and have extras in the event one does. Originally Posted By -OdieGreen-: My phosphate and nitride examples have a groove where as I’d say my chrome ones are more of a light surface scratch. I’m not worried about it either way. As stated I’ve never had one break and have extras in the event one does. My Daniel Defense had a groove after about 400 rounds. I replaced it with a colt cam pin, but haven't shot it yet. |
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Originally Posted By -OdieGreen-: Chrome lined cam pin after a minimum of 5,000 rounds, probably a bit more but lost track. https://www.ar15.com/media/mediaFiles/61399/IMG_3356_jpeg-3185186.JPGhttps://www.ar15.com/media/mediaFiles/61399/IMG_3357_jpeg-3185188.JPG I’ve never had a cam pin break but I suspect the chromed examples are less susceptible based on surface wear. Hardening or inconsistencies who knows, but you can barely feel the wear with a finger nail. If not obvious, I don’t pay attention to orientation. Don't forget that if it's not baked after chrome plating, which some people like to skip wherever possible the part is made more brittle Whose make chrome pin is that? |
| I just ordered from specialized armament 3 days ago, everything but the extractor from the suggested parts. I already have spare springs. I did email them asking to send me a buffer tube without nicks and I know they don't take kindly to something as innocuous as people asking for an ETA. no reply and also no charge on the card yet not even authorization. I wonder if they took offense to my request |
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Originally Posted By casktcrw: I just ordered from specialized armament 3 days ago, everything but the extractor from the suggested parts. I already have spare springs. I did email them asking to send me a buffer tube without nicks and I know they don't take kindly to something as innocuous as people asking for an ETA. no reply and also no charge on the card yet not even authorization. I wonder if they took offense to my request Sgt Elmore's customer service is about as bad if not the worst as anyone in the entire gun industry. And their website sux. Every time I click on anything on their site I get the circle of death for 15-20 seconds before it responds. Only website that does this to me. They dont ask for the 3 digit number on your credit card until after you place the order, then they send you an email asking you to spell it out or call and leave it on their voicemail lol. nine, eight, one and dont forget the commas. |
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Originally Posted By OTDR: Sgt Elmore's customer service is about as bad if not the worst as anyone in the entire gun industry. And their website sux. Every time I click on anything on their site I get the circle of death for 15-20 seconds before it responds. Only website that does this to me. They dont ask for the 3 digit number on your credit card until after you place the order, then they send you an email asking you to spell it out or call and leave it on their voicemail lol. nine, eight, one and dont forget the commas. What commas? |
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Like i say my zipcode zero comma two comma eight comma etc?? Im so lost! No buffer tube for you. I was trying to get another one of those Mark 18 tubes but somebody tried to sell me one that was new but had dings all over the place. That's what I'm trying to avoid. |
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Originally Posted By casktcrw: Don't forget that if it's not baked after chrome plating, which some people like to skip wherever possible the part is made more brittle Whose make chrome pin is that? No idea at this point. 60% chance it’s Microbest, 40% chance it’s Brownell’s. |
https://instagram.com/_odiegreen_?igshid=OGQ5ZDc2ODk2ZA==
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Originally Posted By casktcrw: Don't forget that if it's not baked after chrome plating, which some people like to skip wherever possible the part is made more brittle Whose make chrome pin is that? Originally Posted By casktcrw: Originally Posted By -OdieGreen-: Chrome lined cam pin after a minimum of 5,000 rounds, probably a bit more but lost track. https://www.ar15.com/media/mediaFiles/61399/IMG_3356_jpeg-3185186.JPGhttps://www.ar15.com/media/mediaFiles/61399/IMG_3357_jpeg-3185188.JPG I’ve never had a cam pin break but I suspect the chromed examples are less susceptible based on surface wear. Hardening or inconsistencies who knows, but you can barely feel the wear with a finger nail. If not obvious, I don’t pay attention to orientation. Don't forget that if it's not baked after chrome plating, which some people like to skip wherever possible the part is made more brittle Whose make chrome pin is that? People love saving $.02/part by skipping hydrogen bakes. I guess it makes them feel smart (I lack perspective, since I'm a dumb ass). I would expect the material that the part is made of to be very brittle, since it's tempered at 625F. I find that to be very suspect. With very few exceptions, no steel should be tempered at or near 500-600F, because it will be severely embrittled. It is supposedly already extremely brittle without being chrome-plated, and chrome-plating it sure as hell isn't improving that. Whether this brittleness actually reveals itself in broken parts is unknown to me. |
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Originally Posted By brownbomber: People love saving $.02/part by skipping hydrogen bakes. I guess it makes them feel smart (I lack perspective, since I'm a dumb ass). I would expect the material that the part is made of to be very brittle, since it's tempered at 625F. I find that to be very suspect. With very few exceptions, no steel should be tempered at or near 500-600F, because it will be severely embrittled. It is supposedly already extremely brittle without being chrome-plated, and chrome-plating it sure as hell isn't improving that. Whether this brittleness actually reveals itself in broken parts is unknown to me. Bad cam pins break at the firing pin hole. |
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Got my specialized armament order, about 3 weeks after ordering. Tube has small scratches, dings, rib tool marks, discontinuities, spiral groove in bore, and a weird impression. My first mk18 tube is the nicest part of that build; this one is my worst tube. Cam pin looks nothing like my other colts. Uneven chamfer like bcm, super rough hole. Everything else I bought as add on, so I'm gonna push for a full refund via cc. https://imgur.com/a/vozMOL4 |
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Elmore fudd is losing it. He says I stole the parts because I told him I'm gonna charge back the purchase. Says he's gonna document that i said handled them, and take pictures of the oil I used to wipe it down. I just can't I'm fucking dying. He didn't even dispute what I said about the parts, just said he didn't care. |
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Just put in back in the same way each reassembly:Attached File |
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Originally Posted By ronemus: That's most likely due to improper heat treatment or choice of steel (soft end product). I had this issue with my first AR 25 years ago, so I bought several to stock as consumables; I haven't had one wear since. Chrome plating isn't necessary - just good metallurgy with proper cleaning and lubrication. I use MolySlide (a light grease with 60% moly) because this is a high-stress area. Chances are they are made correctly and from the correct materials . . . AISI 4340 steel through hardened and tempered to 45 - 48 RHc is going to show some wear when it rubs constantly on some surface hardened steel that is 60 - 61 RHc. Keep it lubricated, it will be fine. |
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Originally Posted By OTDR: SOTAR nonsense. ^^ This ^^ When the pin is install in the carrier, the front-right 45 degree area will see the most wear (see below). This is from the cam slot unlocking the bolt by pushing on the pin. At 180 degrees from that primary wear mark will be a similar mark cause by the cam slot rotating the bolt closed. The wear is restricted to these area. The usual areas of surface finish loss are impact, not sliding wear. The pin is not going to wear down and get any smaller, so the looseness of the cam pin fit is going to stay pretty much the same. Randomly installing the pin, just make the pin wear even on the front and back.  |
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Never had a cam pin break but had lots of scoring just like the ones above. Used two separate chromed ones I got on Commercial Row for National Match M16s -- at first they polish, then they wore the same way. I suppose you can replace them when you replace the barrel. |
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Originally Posted By lysanderxiii: ^^ This ^^ When the pin is install in the carrier, the front-right 45 degree area will see the most wear (see below). This is from the cam slot unlocking the bolt by pushing on the pin. At 180 degrees from that primary wear mark will be a similar mark cause by the cam slot rotating the bolt closed. The wear is restricted to these area. The usual areas of surface finish loss are impact, not sliding wear. The pin is not going to wear down and get any smaller, so the looseness of the cam pin fit is going to stay pretty much the same. Randomly installing the pin, just make the pin wear even on the front and back. https://i.imgur.com/NaMNp0n.jpg Honestly, this is what I've always thought. Over the course of a given round count there is going to be a certain amount of wear. Does it really make any difference if it's distributed over both sides instead of one? |
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I don't want to sound like I'm coming off the wrong way, but I'm not exactly grasping alot of what's happening in this thread. We're talking about a part where a known good quality one can be had for 10 bucks... or less. I'm also not exactly rolling in money and even I have a couple spares around here. If the need should arise, put in a new one. 
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Like every other small part for ARs, I just choose to keep a stock of spares in my range/armorer's box and not fret over it. For a couple hundred bucks you can get spares of everything plus a whole spare BCG. If you're concerned, keep a whole spare bolt and cam pin in the grip or something. Coincidentally, I've had a rifle turn into a single shot from a broken gas key screw but never from a cam pin, gas ring, or other BCG part. |
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