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Posted: 7/29/2022 5:03:31 PM EDT
| Just paid for my second machine gun. First was a MAC 10 I bought 2 years ago and just picked up a M16. My questions is are the KNS sear protectors and trigger pins a good investment or snake oil? I know the trigger pins are worthless on semi autos. |
"I am not an Operator but I play one on AR15.com"
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Originally Posted By osprey21: Personally I'll go with how Stoner and Sullivan designed the gun, and that's so the hammer and trigger pins would float (Rotate) each time the weapon is fired or the bolt cycles. Wrong. Trigger and hammer are supposed to pivot/rotate on their respective pins. Read col. 2, lines 43-46 and 67-69. https://pdfpiw.uspto.gov/.piw?PageNum=0&docid=03045555&IDKey=EC76394777C5%0D%0A&HomeUrl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO1%2526Sect2%3DHITOFF%2526d%3DPALL%2526p%3D1%2526u%3D%25252Fnetahtml%25252FPTO%25252Fsrchnum.htm%2526r%3D1%2526f%3DG%2526l%3D50%2526s1%3D3045555.PN.%2526OS%3DPN%2F3045555%2526RS%3DPN%2F3045555 MHO, YMMV, etc. Be well. |
"I am not an Operator but I play one on AR15.com"
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Originally Posted By Clicker58: It's not obvious to tell when you've broken them so I no longer run the KNS trigger or hammer pins. Now the sear pin (IMO) is a great idea on a conversion gun and I do run one of those, doubt you'd need one on an original Colt M16. I went thru the same thought process and after a lot of research I came to same conclusion. I do not use them ony RR. |
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Originally Posted By uniquesnd: So they are a good idea then? Super confused now! So what are you doing with the gun? Colt nonramped 9mm blowback, half worn-out Mark 18 upper, or maybe Colt open bolt conversion? These would tend to be hard on the lower. Especially in the hammer pin location the standard fire control pins are strong but brittle. The is also the issue of the link between the KNS trigger pin and the hammer pin. That link wore the anodizing on the outside of my Colt M16. Colt made stainless steel pins for their 9mm blowback guns. The stainless steel pins have more give and are not brittle like the standard pins. Ultimately no one is going to tell you what you should do. Especially with a conversion lower, fire control hole damage can always be repaired. YMMV. Scott |
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Originally Posted By canon3825: So what are you doing with the gun? Colt nonramped 9mm blowback, half worn-out Mark 18 upper, or maybe Colt open bolt conversion? These would tend to be hard on the lower. Especially in the hammer pin location the standard fire control pins are strong but brittle. The is also the issue of the link between the KNS trigger pin and the hammer pin. That link wore the anodizing on the outside of my Colt M16. Colt made stainless steel pins for their 9mm blowback guns. The stainless steel pins have more give and are not brittle like the standard pins. Ultimately no one is going to tell you what you should do. Especially with a conversion lower, fire control hole damage can always be repaired. YMMV. Scott Originally Posted By canon3825: Originally Posted By uniquesnd: So they are a good idea then? Super confused now! So what are you doing with the gun? Colt nonramped 9mm blowback, half worn-out Mark 18 upper, or maybe Colt open bolt conversion? These would tend to be hard on the lower. Especially in the hammer pin location the standard fire control pins are strong but brittle. The is also the issue of the link between the KNS trigger pin and the hammer pin. That link wore the anodizing on the outside of my Colt M16. Colt made stainless steel pins for their 9mm blowback guns. The stainless steel pins have more give and are not brittle like the standard pins. Ultimately no one is going to tell you what you should do. Especially with a conversion lower, fire control hole damage can always be repaired. YMMV. Scott Just dumping mags probably, I have awhile before I get the gun. Money is sent and forms are filed but it was an out of state deal. |
"I am not an Operator but I play one on AR15.com"
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Originally Posted By uniquesnd: Just paid for my second machine gun. First was a MAC 10 I bought 2 years ago and just picked up a M16. My questions is are the KNS sear protectors and trigger pins a good investment or snake oil? I know the trigger pins are worthless on semi autos. I have a friend that was an Army armorer in Vietnam and later in the Army reserve. I asked him about hole "egg holing" in M16s. He said there were gages to check for hole wear, but he never personally saw any M16s that had that wear. When I was in basic those M16A1s on the practice range were fired 7 days a week. I would think if there was a problem with wear it would have been addressed with the M16A2 or the M4. I bought my first personal M16A1 in 1980 and shot it a LOT, never had a problem with wear or breakage of anything. |
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Originally Posted By jhoffman: I have a friend that was an Army armorer in Vietnam and later in the Army reserve. I asked him about hole "egg holing" in M16s. He said there were gages to check for hole wear, but he never personally saw any M16s that had that wear. When I was in basic those M16A1s on the practice range were fired 7 days a week. I would think if there was a problem with wear it would have been addressed with the M16A2 or the M4. I bought my first personal M16A1 in 1980 and shot it a LOT, never had a problem with wear or breakage of anything. Originally Posted By jhoffman: Originally Posted By uniquesnd: Just paid for my second machine gun. First was a MAC 10 I bought 2 years ago and just picked up a M16. My questions is are the KNS sear protectors and trigger pins a good investment or snake oil? I know the trigger pins are worthless on semi autos. I have a friend that was an Army armorer in Vietnam and later in the Army reserve. I asked him about hole "egg holing" in M16s. He said there were gages to check for hole wear, but he never personally saw any M16s that had that wear. When I was in basic those M16A1s on the practice range were fired 7 days a week. I would think if there was a problem with wear it would have been addressed with the M16A2 or the M4. I bought my first personal M16A1 in 1980 and shot it a LOT, never had a problem with wear or breakage of anything. I DID see that wear especially in burst guns. Never a sear hole, but definitely egged out M16A2 and M4 hammer holes. |
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For some specifically documented accounts of what wears out or can get damaged, and related round counts, one may wish to peruse this thread: https://www.ar15.com/forums/AR-15/High-round-count-AR-M4-s-over-100-000-rounds-and-how-they-have-handled-on-our-range/118-677135/ Note, a lot of the discussion is not related to M16s, but may still be of interest; and there aren't any recent substantive updates, but the last I knew, the laws of math, chemistry, metallurgy, and physics haven't changed. MHO, YMMV, etc. Be well. |
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Originally Posted By SecondAmend: For some specifically documented accounts of what wears out or can get damaged, and related round counts, one may wish to peruse this thread: https://www.ar15.com/forums/AR-15/High-round-count-AR-M4-s-over-100-000-rounds-and-how-they-have-handled-on-our-range/118-677135/ Note, a lot of the discussion is not related to M16s, but may still be of interest; and there aren't any recent substantive updates, but the last I knew, the laws of math, chemistry, metallurgy, and physics haven't changed. MHO, YMMV, etc. Be well. Exactly consistent with what I saw on the M16 platform. Trigger holes never wore out that I knew of, but hammer pins became loose and were only captive by the spring at about 20,000 rounds. |
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Originally Posted By LavaDomane: Exactly consistent with what I saw on the M16 platform. Trigger holes never wore out that I knew of, but hammer pins became loose and were only captive by the spring at about 20,000 rounds. Originally Posted By LavaDomane: Originally Posted By SecondAmend: For some specifically documented accounts of what wears out or can get damaged, and related round counts, one may wish to peruse this thread: https://www.ar15.com/forums/AR-15/High-round-count-AR-M4-s-over-100-000-rounds-and-how-they-have-handled-on-our-range/118-677135/ Note, a lot of the discussion is not related to M16s, but may still be of interest; and there aren't any recent substantive updates, but the last I knew, the laws of math, chemistry, metallurgy, and physics haven't changed. MHO, YMMV, etc. Be well. Exactly consistent with what I saw on the M16 platform. Trigger holes never wore out that I knew of, but hammer pins became loose and were only captive by the spring at about 20,000 rounds. To my understanding of what Henderson posted, the hammer hole enlargement was only observed in two short barrel (i.e., high gas pressure) applications; and the enlargement was mitigated and no further enlargement was observed by the implementation of KNS pins such that the receivers with enlarged hammer pin holes continued to be used with no further ill effects to firearm operation or to the receivers. FWIW, I was also encouraged by their report that they only use standard mil spec SS recoil springs and get about 150,000 rounds of use before replacement is performed. MHO, YMMV, etc. |
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Originally Posted By SecondAmend: For some specifically documented accounts of what wears out or can get damaged, and related round counts, one may wish to peruse this thread: https://www.ar15.com/forums/AR-15/High-round-count-AR-M4-s-over-100-000-rounds-and-how-they-have-handled-on-our-range/118-677135/ Note, a lot of the discussion is not related to M16s, but may still be of interest; and there aren't any recent substantive updates, but the last I knew, the laws of math, chemistry, metallurgy, and physics haven't changed. MHO, YMMV, etc. Be well. Didn't these guys, or some rental range, do a Youtube video on breakage/wear of a variety of weapons? |
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Originally Posted By SecondAmend: To my understanding of what Henderson posted, the hammer hole enlargement was only observed in two short barrel (i.e., high gas pressure) applications; and the enlargement was mitigated and no further enlargement was observed by the implementation of KNS pins such that the receivers with enlarged hammer pin holes continued to be used with no further ill effects to firearm operation or to the receivers. FWIW, I was also encouraged by their report that they only use standard mil spec SS recoil springs and get about 150,000 rounds of use before replacement is performed. MHO, YMMV, etc. Originally Posted By SecondAmend: Originally Posted By LavaDomane: Originally Posted By SecondAmend: For some specifically documented accounts of what wears out or can get damaged, and related round counts, one may wish to peruse this thread: https://www.ar15.com/forums/AR-15/High-round-count-AR-M4-s-over-100-000-rounds-and-how-they-have-handled-on-our-range/118-677135/ Note, a lot of the discussion is not related to M16s, but may still be of interest; and there aren't any recent substantive updates, but the last I knew, the laws of math, chemistry, metallurgy, and physics haven't changed. MHO, YMMV, etc. Be well. Exactly consistent with what I saw on the M16 platform. Trigger holes never wore out that I knew of, but hammer pins became loose and were only captive by the spring at about 20,000 rounds. To my understanding of what Henderson posted, the hammer hole enlargement was only observed in two short barrel (i.e., high gas pressure) applications; and the enlargement was mitigated and no further enlargement was observed by the implementation of KNS pins such that the receivers with enlarged hammer pin holes continued to be used with no further ill effects to firearm operation or to the receivers. FWIW, I was also encouraged by their report that they only use standard mil spec SS recoil springs and get about 150,000 rounds of use before replacement is performed. MHO, YMMV, etc. That very well could have been in their case. I missed reading that part that it was isolated to an SBR. We saw it predominantly on the very first FN M16A2 rifles, and on a LOT of the GAU 5 lowers which were converted to burst guns with M4 barrels in the early 2000's IIRC. We replaced demilled and replaced something like 48 receivers one year because they don't do depot level repairs in the Air Force in most cases. They just demil and replace. This was just after the time we were torch cutting brand new 601's and Model 614's that were largely untouched guns. We blew through a LOT of ammo firing the GAU's on full auto with the moderators on them because we were just torch cutting them anyway. |
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