R4 barrel issue

The #1 community for Gun Owners in Indiana

Member Benefits:

  • Fewer Ads!
  • Discuss all aspects of firearm ownership
  • Discuss anti-gun legislation
  • Buy, sell, and trade in the classified section
  • Chat with Local gun shops, ranges, trainers & other businesses
  • Discover free outdoor shooting areas
  • View up to date on firearm-related events
  • Share photos & video with other members
  • ...and so much more!
  • HavokCycle

    Master
    Rating - 100%
    2   0   0
    Nov 10, 2012
    2,087
    38
    Zionsville
    I picked up an r4 profile barrel from my LGS, just to make something out of the parts I have laying around.
    I intend to put on a regular front sight on, not a gas block, and grabbed one from my parts drawer. Not sure what it came off of but it has the correct .750 diameter - I think. I had a pencil barrel at one point but those run .625

    so my issue is, the FSB slides on tightly, but there is zero room for the drift pins to go in. On one hole I can see the barrel intruding on half the space of the drift pin hole, the other side is nearly completely blocked.

    Ive never played with an R4 barrel before so I'm slightly lost. Do I need to pick up a different FSB or does this barrel need to be milled/drilled to accept?

    when I look at my other platforms with a .750 barrel it looks like it would be the same issue, but it's been too long since I've built one with a front sight for me to remember how it went together. Clearly remember not cutting anything tho.
     

    j706

    Master
    Site Supporter
    Rating - 100%
    60   0   1
    Dec 4, 2008
    4,159
    48
    Lizton
    I assume with R4 and front sight sizes you are referring to an Ar type rifle. If so and if the front sight did not come off of that barrel originally therein lies your problem. Most AR front sights are held in place by taper pins and are individually drilled when installed.
     
    Top Bottom