Quantcast

Bolt-head differences (AR-15/M16)

Discussion in 'NFA Firearms and Accessories' started by EyeForEye, Apr 15, 2019.

  1. EyeForEye

    EyeForEye Member

    Joined:
    Apr 15, 2019
    Messages:
    2
    Hello everyone, I was recently researching on the topic of the differences between M16 and AR-15 general receiver parts, and while I have found out that M16 bolt carrier groups differ from AR-15 ones, I could not find any info on the difference of the bolt-head, maybe someone here knows.

    So basically, is there any difference between an M16 bolt-head and an AR-15 bolt-head?
    Say as an example, I have an M16 bolt head, would that fit into an AR-15 bolt carrier group? And vice versa?

    Thank you.
     
  2. Hoser

    Hoser Moderator

    Joined:
    Dec 29, 2002
    Messages:
    1,256
    Location:
    Colorado
    The bolt is the same. It is the carrier that is different.
     
    EyeForEye likes this.
  3. EyeForEye

    EyeForEye Member

    Joined:
    Apr 15, 2019
    Messages:
    2
    That would make sense as to why I couldn't find anything regarding that :D
    Thank you! :)
     
  4. Theohazard

    Theohazard Member

    Joined:
    Feb 24, 2014
    Messages:
    1,560
    Location:
    Western PA
    Also keep in mind that many AR-15s come with M16 bolt carriers (often referred to as full-auto bolt carriers). The different types of bolt carriers are completely interchangeable, the only thing is that a semi-auto bolt carrier won’t trip the auto-sear on an M16/M4.
     
    Last edited: Apr 15, 2019
    Ryanxia likes this.
  5. AlexanderA
    • Contributing Member

    AlexanderA Member

    Joined:
    Feb 27, 2011
    Messages:
    5,229
    Location:
    Virginia
    Paranoia about bolt carriers has run in cycles. Originally, to get approval for the semiautomatic AR-15, Colt cut back the rear of the M16 bolt carrier so it wouldn't trip an auto sear. Later, it introduced the "beveled" or "unshrouded" carrier as part of its system to prevent hammer follow-down. Still later, it made a carrier with the entire rear open at the bottom, to prevent an adapter from being added to trip a DIAS.

    ATF, at one time, ruled that a full-auto bolt carrier was one of a list of "no-no" parts that were not supposed to be found on a semiauto gun (the others included the selector, hammer, trigger, and disconnector). Colt apparently built up an excess inventory of full-auto carriers and it finally got ATF to relent and allow them to be used on semiauto guns. These have since become the industry standard.
     
    Theohazard likes this.
  6. 243winxb

    243winxb Member

    Joined:
    Jul 7, 2004
    Messages:
    10,568
    Location:
    Hopewell Big Woods
    The barrel extension and bolt set the chambers headspace. This headspace should be checked with a gauge.

    Different bolt= different headspace.
     
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice