Broken roll pin help

Discussion in 'Auto & Semi-Auto Discussion' started by boudmanj, Jan 21, 2014.

  1. boudmanj

    boudmanj New Member

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    I have a broken roll pin on my ar and have no idea how it happened. Has anyone experienced this, what causes it
     
  2. JonM

    JonM Moderator

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    Ar15 have a few of em which one did you break??

    Drift the broken bit out. Order a new one and don't mash it as hard this time ;)
     

  3. Sniper03

    Sniper03 Supporting Member Supporter

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    Like Jon advised! Which one? How about a picture. Can't see it being a major issue?

    03
     
  4. boudmanj

    boudmanj New Member

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    The one that holds the hammer, broke in the middle

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  5. John_Deer

    John_Deer New Member

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    Last edited: Jan 21, 2014
  6. boudmanj

    boudmanj New Member

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    It was a dpms parts kit and it's a cheap pin, I'm wondering if stress was the factor, I have another one I built using a palmetto parts kit, more rounds through it and runs like a top

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  7. boudmanj

    boudmanj New Member

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    This is the pin, broke at the middle groove

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    Attached Files:

  8. string1946

    string1946 New Member

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    Ok thats not really a roll pin. Its the hammer pivot pin and it broke at the grove for the hammer J spring. Roll pins would be the ones holding the rear of the trigger guard and the bolt catch. I have never had one break but thats just me. When you replace it squirt the hole thru the hammer full of a good grease before tapping the pin in. Actually an LR 308 uses a screw for the bolt catch and I wish all AR's did that as I don't like hammering on my guns if I can help it.
     
    Last edited: Jan 22, 2014
  9. duddie10

    duddie10 New Member

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    Is this a common problem? I dont think ive seen this happen before.

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  10. boudmanj

    boudmanj New Member

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    I've seen it once before, it's not like I beat the hell out of the pin when I built the gun, I'm thinking it's just cheaply made. It doesn't feel as hardy as the one in my other build

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  11. mountainman13

    mountainman13 New Member

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    Cheap part, broke at the stress point.

    better judged by twelve than carried by six.
     
  12. Jpyle

    Jpyle New Member

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    Cheaper pins may not fit the hole to spec which may lead to unnecessary torque on the pin. These are the best $5 I ever spent...

    http://www.knsprecisioninc.com/gun-parts-and-accessories/trigger-hammer-pins/replacement-trigger-hammer-pins.html
     
  13. Hookeye

    Hookeye Active Member

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    If you've seen two I'd probably look at getting a different supplier ;)
     
  14. string1946

    string1946 New Member

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    I think I'm going to use the anti-walk pins from now on. No grooves to weaken the pin and only $16 per set.

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  15. purehavoc

    purehavoc New Member

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    Exactly , I had one rifle that I was using really really light trigger and hammer springs in and because they were as light as they were they evidentally did not stay in the grooves of the pin well , I had a trigger pin slip out and drop the trigger sideways in the receiver , you know the rest of the story , it was the longest 5 seconds of hang on and keep it on target until it unloaded . I bought 6 sets of KNS pins shortly after that fiasco
     
  16. purehavoc

    purehavoc New Member

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    Hey man if you need one of these let me know where your at and I will throw one in the mail . Free just PM me your address
     
  17. JonM

    JonM Moderator

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    Nah. Prolly was a dpms lpk. Not exactly quality. Be interested in seeing good closeups of the broken ends.

    The grooves in the trigger and hammer pins are for the legs of the springs. They prevent the pins from walking. You only need kns type pins if your using a trigger pack like a timney or cmc.
     
  18. purehavoc

    purehavoc New Member

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    Jon ,
    I have to disagree on this one. You have a incident like mine and one may deem them very necessary . Especially with all the light springs out there on the market . I had no intentions of ever putting them on because I thought they were more for looks beside just holding pins in . I was very wrong . For the little bit they cost they are worth having to me . Now you leave in the mil spec springs one may never have a problem .
     
  19. Sniper03

    Sniper03 Supporting Member Supporter

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    boudmanj,

    Not to offend anyone but this is not a roll pin just for information. It is a Hammer Pin which is a solid pin. That was what threw me at first when you said roll pin. But no problem we all learn from posting the Threads.
    First of all, the J Wire or sometimes called the J Spring is what holds the Trigger Pin in place. And your Pin broke right at the Notch which the J Wire locks into. If the J Wire is weak or broken it will allow the Hammer Pin to walk out of the Receiver and one never needs to attempt to repair it! Just replace the Hammer with a new J Wire in it. From your picture the Trigger Spring looks to be the standard spring and is installed correctly on the Hammer. And when installed in the Receiver the Hammer Spring Legs should be on top of the Trigger Pin and along both sides and against the inside walls of the Receiver and in the Notch on top of the Trigger Pin. I off hand would say you had an inferior Hammer Pin! DPMS of late has been producing some parts that were less than satisfactory. I have seen on 3 occasions with their lower parts kits where the Trigger (Box) tail section of the Trigger where the Disconector Spring goes that was around 15 degrees off center instead of perfectly straight as they should be. So I think you got a bad pin! However if it happens again you probably have a tolerance problem in regard to the Hammer, Carrier and or other fire control parts. I would suggest just replacing the Hammer Pin and probably while I was at it I would replace the Trigger Pin also just in case! Another great item is the KNS Anti-Rotate Trigger and Hammer Pin Set from KNS. They will also smooth out any trigger even the standard trigger, NM Trigger or Adjustable Trigger systems. But as stated the break you experienced is not a normal occurrence!

    03
     
  20. boudmanj

    boudmanj New Member

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    I guess I should've said this earlier, but thanks for the help, got fixed, I know what the problem is, ****ty pin, was just askin if anyone has had the same problem with that companies product, thank you again

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