G&R Tactical
Page 4 of 4 FirstFirst ... 234
Results 31 to 33 of 33

Thread: NSWC testing on gas systems. CARBINE VS MID-LENGTH

  1. #31
    Join Date
    Sep 2007
    Feedback Score
    14 (100%)
    Quote Originally Posted by sinister View Post
    Accuracy starts to degrade quicker on the 7" carbine gas length as the downrange side of the gas port erodes quicker. You're talking a significant port pressure delta in those two inches' difference between 7 and 9 inches.
    I used to have those charts... out of quick load. They'd show the pressure levels throughout the barrel... 3-5k reduction from carbine to mid if I remember right.
    "You people have too much time on your hands." - scottryan

  2. #32
    Join Date
    Oct 2006
    College Station, Texas
    Feedback Score
    5 (100%)
    Armalite had a very good pressure curve graphic posted on their tech notes. This is a variation (63-grains being close to legacy M855 Green Tip):

  3. #33
    Join Date
    Jan 2013
    Black Hills, South Dakota
    Feedback Score
    Quote Originally Posted by ABNAK View Post
    That MIGHT, maybe, be the only answer that makes sense. i.e. it's CHF vs non-CHF. Maybe......

    EDIT: *might* affect accuracy but not velocity.

    Wonder who made the CHF barrels for this test?
    If you have a projectile that enters the rifling at an non optimal angle due to a less than concentric chamber, muzzle velocity won’t be affected but downrange performance of that ever so slightly deformed round with an ever so slight oblong movement to its spiral rotation will show degraded accuracy and probably velocity.

Page 4 of 4 FirstFirst ... 234


Posting Permissions

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