In order to participate in the GunBroker Member forums, you must be logged in with your GunBroker.com account. Click the sign-in button at the top right of the forums page to get connected.

AR 15 pin diameter change question

5mmgunguy5mmgunguy Member Posts: 3,853
edited July 2010 in Ask the Experts
When Colt made the pin diameter change...did they go from .154 to .170 or was it .170 to .154?

Comments

  • Laredo LeftyLaredo Lefty Member Posts: 13,452 ✭✭✭
    edited November -1
    It was large to small. There is an adapter pin that can be used to mate an upper of one size to a lower of the other size.
  • TxsTxs Member Posts: 18,801
    edited November -1
    Original AR15 and milspec M16 hammer and trigger pins are .154 in. Colt increased these to .170 in. to preclude use of these parts in their semiauto AR receivers.

    For this same reason they bumped their milspec size takedown pin from .250 to .312, but later dropped this.
  • dcs shootersdcs shooters Member Posts: 10,969
    edited November -1
    quote:Originally posted by Txs
    Original AR15 and milspec M16 hammer and trigger pins are .154 in. Colt increased these to .170 in. to preclude use of these parts in their semiauto AR receivers.

    For this same reason they bumped their milspec size takedown pin from .250 to .312, but later dropped this.


    Actually the takedown and pivot pins went to .250 from .312.
  • TxsTxs Member Posts: 18,801
    edited November -1
    quote:Originally posted by dcs shooters
    quote:Originally posted by Txs
    Original AR15 and milspec M16 hammer and trigger pins are .154 in. Colt increased these to .170 in. to preclude use of these parts in their semiauto AR receivers.

    For this same reason they bumped their milspec size takedown pin from .250 to .312, but later dropped this.


    Actually the takedown and pivot pins went to .250 from .312.
    I've realized I missspoke.

    I intended to say Colt semiauto AR pivot pins went from .250 to .312 and then back to down to .250.

    Colt's takedown pins have always been milspec .250 diameter regardless of the model.
Sign In or Register to comment.