Page 1 of 4 123 ... LastLast
Results 1 to 10 of 33

Thread: BCM lw BFH barrel vs. Standard govt. profile barrel(all things considered)

  1. #1
    Join Date
    Nov 2008
    Posts
    680
    Feedback Score
    10 (100%)

    BCM lw BFH barrel vs. Standard govt. profile barrel(all things considered)

    Planning a 14.5 build and have some technical questions.

    I've read over a over that if you want to shoot at higher rates of speed then go with standard/govt profile barrel because it doesn't get hot as fast. But the logic here seems flawed in that yes it will take longer to get hot but will also take much longer to dissipate the heat once it is hot. Am I right?

    Second, people say (mostly assume) that once the lightweight barrel IS hot, it is less accurate than a govt. profile barrel is.... I could see this being true IF a government profile barrel were the same .750ish diameter the the entire length of the barrel instead of basically being a "lightweight profile" from the gasblock to the receiver leaving the heavy end ass backwards to cause more barrel sag at higher temps than a lightweight barrel would... Or is it my logic that is backward?

    While we are talking about heat, and "getting hot faster" on a lightweight barrel, since most people's support hand placement is behind the gasblock anyway does heat really matter from a comfort standpoint since that section of either barrel would be equally hot under a rail?

    And finally IF the govt profile barrel does in fact hold accuracy better at higher temps from rapid strings of fire. Would getting a BFH lw barrel correct that problem by adding stiffness and in the end being better all around than a standard govt profile barrel?

    I did do a search btw coming up with only the following thread which did not answer any of these specific questions
    https://www.m4carbine.net/showthread...ight=Lw+barrel
    Last edited by mikeith; 11-01-13 at 22:41.

  2. #2
    Join Date
    Jan 2008
    Location
    AZ-Waging jihad against crappy AR's.
    Posts
    24,900
    Feedback Score
    104 (100%)
    I suggest the following;

    Look at the barrel of a SCAR, AK47, M16A1 and probably the FN FAL.



    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

  3. #3
    Join Date
    Sep 2012
    Location
    Austin, TX
    Posts
    315
    Feedback Score
    2 (100%)
    Ive got a 14.5 LW DD mid barrel and have dumped a couple mags pretty quick through it. With the NSR it does get a little warm but I didn't see a big loss in accuracy with a RDS. With a scope I might be able to but I still had no problem hitting center of mass quickly at 100yds. The LW is worth it to me for the lighter gun and quicker swing. Its pleasant to lug around the deer lease during the summer for hogs.

  4. #4
    Join Date
    Dec 2012
    Location
    NW WA
    Posts
    348
    Feedback Score
    1 (100%)
    SOCOM profile

  5. #5
    Join Date
    Jan 2011
    Location
    South Texas
    Posts
    2,740
    Feedback Score
    52 (98%)
    Would it make any sense if you made the last half of a lightweight barrel a little thicker?

    No?

    It would if you needed to mount an M203.

    The profile has nothing to do with heat or accuracy.

  6. #6
    Join Date
    Dec 2009
    Location
    Utah
    Posts
    8,799
    Feedback Score
    3 (100%)
    Quote Originally Posted by mikeith View Post
    Planning a 14.5 build and have some technical questions.

    I've read over a over that if you want to shoot at higher rates of speed then go with standard/govt profile barrel because it doesn't get hot as fast. But the logic here seems flawed in that yes it will take longer to get hot but will also take much longer to dissipate the heat once it is hot. Am I right?
    Man, I wish folks would look up the laws of thermo dynamics. If your're talking temperature, lets say you heat up a barrel 16" long and 2" in diameter and a barrel of the same length but only 1 inch in diameter to 250*, the 2 inch barrel will contain more heat and will take longer to cool off to ambient temperature. However, if you heat both barrels with the same amount of heat, say 250 BTUs (British Thermal Units), the 2" barrel will be cooler than the 1" barrel because it has more material and will cool off to ambient temperature quicker because it has more surface to radiate heat

    Second, people say (mostly assume) that once the lightweight barrel IS hot, it is less accurate than a govt. profile barrel is
    In general, it should make little difference because both barrels are roughly the same diameter where it matters when it comes to heat- close to the chamber. However, every barrel is a law unto itself and barrel quality is a factor as to how a barrel reacts to heat
    The number of folks on my Full Of Shit list grows everyday

    http://i115.photobucket.com/albums/n289/SgtSongDog/AR%20Carbine/DSC_0114.jpg
    I am American

  7. #7
    Join Date
    Jun 2006
    Posts
    1,760
    Feedback Score
    7 (100%)
    Quote Originally Posted by samuse View Post
    Would it make any sense if you made the last half of a lightweight barrel a little thicker?

    No?

    It would if you needed to mount an M203.

    The profile has nothing to do with heat or accuracy.
    Lightweight barrels can take an M203 just fine.

  8. #8
    Join Date
    Oct 2012
    Location
    SWFL
    Posts
    3,112
    Feedback Score
    6 (100%)
    Get the lightweight barrel and stop over thinking it!

  9. #9
    Join Date
    Nov 2007
    Location
    Miami, FL
    Posts
    567
    Feedback Score
    0
    Why did I go with a BCM BFH? Because the LW was already pricey and the BFH was 'only' $70 more and there were some (not a lot) comments concerning the shift in POI of their LW barrel.





    .
    Dan Miami, FL

  10. #10
    Join Date
    Jan 2013
    Posts
    90
    Feedback Score
    1 (100%)
    While I have not shot the BCM BFH LW for accuracy (just shot a few rounds out of a buddies gun) I do have the BCM BFH GOV barrel and have shot it for "accuracy". I was shooting my GOV barrel with a 3-9x scope at 500yds on 11" steel. From the start to the end of the 2 mags or so, the poi shifted a lot.
    I started with about a 3-4 mil vert hold off. By the end I was down to between a 1.5-2 mil hold off with a reduce percentage of hits.

    There were other factors such as wind gusts so not all of the reduction in accuracy came from the barrel heating up.

    Now I have switched out to an aimpoint so Im not looking for that accuracy.

Page 1 of 4 123 ... 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
  •