Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 38

Thread: Undergassed?

  1. #11
    Join Date
    Apr 2009
    Location
    Wisconsin
    Posts
    2,908
    Feedback Score
    8 (100%)
    Both of my BCM midlength uppers have .065" ports.
    They are both of the 16" flavor.
    Quote Originally Posted by scottryan View Post
    Anybody that owns or sells pistol versions of assault rifles is a bottom feeder, irregardless of the ban status of certain ammunition.

    They are illigetimate weapons that have no real purpose other than to attract retards to the gun community.

  2. #12
    Join Date
    Sep 2007
    Location
    AZ
    Posts
    27,217
    Feedback Score
    14 (100%)
    Quote Originally Posted by polymorpheous View Post
    Both of my BCM midlength uppers have .065" ports.
    They are both of the 16" flavor.
    So a 14.5 would need to be in the 7 hole at least.
    "You people have too much time on your hands." - scottryan

  3. #13
    Join Date
    Apr 2009
    Location
    Wisconsin
    Posts
    2,908
    Feedback Score
    8 (100%)

    Question

    Quote Originally Posted by markm View Post
    So a 14.5 would need to be in the 7 hole at least.
    For the shorter dwell time, yes.

    Is there some sort of ratio that manufacturers go off to figure port size in relation to dwell time.
    Quote Originally Posted by scottryan View Post
    Anybody that owns or sells pistol versions of assault rifles is a bottom feeder, irregardless of the ban status of certain ammunition.

    They are illigetimate weapons that have no real purpose other than to attract retards to the gun community.

  4. #14
    Join Date
    Apr 2009
    Location
    Washington State
    Posts
    473
    Feedback Score
    0
    Quote Originally Posted by CarlosDJackal View Post

    Are you the same Carlos from down around Vancouver, WA?

    I've only run across a gas tube with an undersize bore once in 20 years, lots of other gas tube problems though. Too bad you have the PF, it helps to look up inside the front sight base and make sure the hole in the FSB lines up with the hole in the gas tube and that the hole is clear and the proper size.
    Last edited by Tweak; 08-15-12 at 12:16.

  5. #15
    Join Date
    Dec 2006
    Location
    Commonwealth of Virginia
    Posts
    3,749
    Feedback Score
    2 (100%)
    Quote Originally Posted by Tweak View Post
    Are you the same Carlos from down around Vancouver, WA?

    I've only run across a gas tube with an undersize bore once in 20 years, lots of other gas tube problems though. Too bad you have the PF, it helps to look up inside the front sight base and make sure the hole in the FSB lines up with the hole in the gas tube and that the hole is clear and the proper size.
    Sorry, different Carlos. I used to live in Vancouver, Canada. But that was almost 30-years ago.
    We must not believe the Evil One when he tells us that there is nothing we can do in the face of violence, injustice and sin. - Pope Francis I

  6. #16
    Join Date
    Jan 2008
    Location
    AZ-Waging jihad against crappy AR's.
    Posts
    24,902
    Feedback Score
    104 (100%)
    I went and checked the numbers and the port size should be around .076.



    Owner/Instructor at Semper Paratus Arms

    Facebook: https://www.facebook.com/SemperParatusArms/

    Semper Paratus Arms AR15 Armorer Course http://www.semperparatusarms.com/cou...-registration/

    M4C Misc. Training and Course Announcements- http://www.m4carbine.net/forumdisplay.php?f=141

    Master Armorer/R&D at SIONICS Weapon Systems- http://sionicsweaponsystems.com

  7. #17
    Join Date
    Nov 2010
    Location
    MI
    Posts
    3,055
    Feedback Score
    21 (100%)
    Quote Originally Posted by Iraqgunz View Post
    I went and checked the numbers and the port size should be around .076.
    Agree
    Black River Tactical
    BRT OPTIMUM HFCL Barrels - Hammer Forged Chrome Lined 11.5", 12.5", 14.5"
    BRT OPTIMUM Barrels - 16" MPR, 14.5" MPC, 12.5" MRC, 11.5" CQB, 9" PDW
    BRT EZTUNE Preset Gas Tubes - CAR and MID
    BRT Covert Comps 7.62, 5.56, 6X, 9mm
    BRT MarkBlue Gas Tubes - BRT EXT, EXC and PDW Lengths
    BRT MicroPin Gas Blocks - .750" & .625"
    BRT MicroTUNE Adjustable Gas Blocks
    BRT CustomTUNE Gas Ports

  8. #18
    Join Date
    Dec 2006
    Location
    Commonwealth of Virginia
    Posts
    3,749
    Feedback Score
    2 (100%)
    Quote Originally Posted by Iraqgunz View Post
    I went and checked the numbers and the port size should be around .076.
    Thanks.
    We must not believe the Evil One when he tells us that there is nothing we can do in the face of violence, injustice and sin. - Pope Francis I

  9. #19
    Join Date
    Sep 2007
    Location
    AZ
    Posts
    27,217
    Feedback Score
    14 (100%)
    I've got a 14.5 middy that's running similar. I pulled the gas tube out of it yesterday and found that the end that goes into the key is about .005" smaller than a used gas tube I had on my bench.

    It looks like the existing gas tube never had the bulb end on the tip of the tube where it goes into the key. And there's a lot of carbon fouling on the 3" of tube forward of the key.

    I have a new tube showing up today. So I'll get to shoot the gun pretty soon. I'm not sure if that .005" is leaking so much gas that it's causing the light cycling or not...
    "You people have too much time on your hands." - scottryan

  10. #20
    Join Date
    Sep 2007
    Location
    AZ
    Posts
    27,217
    Feedback Score
    14 (100%)
    Are you able to see any of these characteristics on your gas tube?
    "You people have too much time on your hands." - scottryan

Page 2 of 4 FirstFirst 1234 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •