Page 1 of 8 123 ... LastLast
Results 1 to 10 of 77

Thread: 13" vs 15" rail for 16" barrel

  1. #1
    Join Date
    Mar 2012
    Location
    NoVA
    Posts
    17
    Feedback Score
    3 (100%)

    13" vs 15" rail for 16" barrel

    I want to order a BCM 16" upper with KMR alpha rail. What are the pros/cons of going with 13" vs 15" for the rail? I am guessing longer sight radius on the 15" at the expense of a little extra weight? Is the extra weight even something I would notice?

    Other pros are that the 15" is in stock right now on BCM's site and I do think the 15" looks a little better.

  2. #2
    Join Date
    Jun 2012
    Posts
    2,587
    Feedback Score
    8 (100%)
    An extra 2" won't make a difference as far as sight radius.

    The weight difference is likely negligible on a rail as light as a KMR.

    It comes down to personal preference.


    Personally, I think a 13" rail on a 16" is enough.
    Last edited by scooter22; 07-01-16 at 01:43.

  3. #3
    Join Date
    Feb 2011
    Location
    Oklahoma
    Posts
    744
    Feedback Score
    10 (100%)
    Do you plan on running a light on this particular gun? The weight of just the rail might not be much, but you also have to account for putting more weight 2" farther out on the rail. Front BUIS, an X300 at 12 o'clock or an M600, panels/hand stop/VFG, etc.. It's going to be pretty far out there weighing the muzzle down. If you are running a RDS is the 2" difference out front going to really matter for a front BUIS you'll likely never use? I have a 13" KMR and pretty long arms and don't think there would be any benefit personally running the 15". I'd think holding your arm out that far for any extended period of time be unnecessarily exhausting.

    Sent from my SM-N910P using Tapatalk

  4. #4
    Join Date
    Jun 2012
    Posts
    2,587
    Feedback Score
    8 (100%)
    Quote Originally Posted by Rogue556 View Post
    Do you plan on running a light on this particular gun? The weight of just the rail might not be much, but you also have to account for putting more weight 2" farther out on the rail. Front BUIS, an X300 at 12 o'clock or an M600, panels/hand stop/VFG, etc.. It's going to be pretty far out there weighing the muzzle down. If you are running a RDS is the 2" difference out front going to really matter for a front BUIS you'll likely never use? I have a 13" KMR and pretty long arms and don't think there would be any benefit personally running the 15". I'd think holding your arm out that far for any extended period of time be unnecessarily exhausting.

    Sent from my SM-N910P using Tapatalk
    I concur.

  5. #5
    Join Date
    Jan 2008
    Location
    AZ-Waging jihad against crappy AR's.
    Posts
    24,902
    Feedback Score
    104 (100%)
    Haynes v. Calvin Klein v. Fruit of the Loom v. Commando. It's all about what you want. If you don't know, then go with the 13" default. I have a 15" Geissele MK8, 14" Centurion Arms CMR, and several other longer rails on my carbines. I have no issues using lights, etc..



    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

  6. #6
    Join Date
    Nov 2013
    Posts
    1,141
    Feedback Score
    18 (100%)
    Preference. I prefer the KMR13 as an X300 on the front is perfect for my reach. If I had a KMR15, I'd still have the light in the same position, so the extra 2" would be wasted.

  7. #7
    Join Date
    Oct 2012
    Location
    Marietta Georgia
    Posts
    593
    Feedback Score
    17 (100%)
    The KMR is a fantastic handguard. Iv got a 15 on one of mine and dont regret it one bit. I could have been just fine with a shorter one, but the shop only had the 15. From a practical stand point i dont see a benefit. From the aesthetics aspect though, its full of win.

  8. #8
    Join Date
    Oct 2012
    Location
    Marietta Georgia
    Posts
    593
    Feedback Score
    17 (100%)

    Trying to decide on a flash suppressor. Maybe there is a member that has both you could try?

  9. #9
    Join Date
    Oct 2012
    Posts
    4,275
    Feedback Score
    10 (92%)
    "Haynes v. Calvin Klein v. Fruit of the Loom v. Commando. It's all about what you want"

    It would be no different if these people went to buy shoes and ask clerk what size most people wear. Would you rather have shoes 1 size too large or one size too small? It is better to have it and not need it than need it and not have it. Get the 15" if you don't know what you want. The extra 2 inches of KMR weighs almost nothing and you don't have to use it.

  10. #10
    Join Date
    Jun 2015
    Posts
    402
    Feedback Score
    202 (100%)
    Personally I like the look of longer rails. I run a 15" rail on a 16" barrel. If your inclination is towards the 15" and it's available you should go for it. I doubt you'll find any drawbacks to it once it's installed. Like others have said, you can mount accessories anywhere on the rail even if the last 2" of space are "wasted".

Page 1 of 8 123 ... 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
  •