White oak armament offers a 17.17 inch gas tube (standard is 15-1/8 inch) that I was thinking of using for a 6.5 creedmoor build with a 26 or 28 inch barrel. Has anyone had experience with the longer tube or should I just use the standard with adjustable gas block? Thanks.
Extra length gas system.
- Thread starter Texar2
- Start date
I built a .260 with a Krieger tube and made a dedicated gas tube +3 inches. My barrel length is 27 inches and feel that the gun would have functioned fine with a standard rifle length gas system and an adjustable gas block. By the way, I reamed the gas port in the barrel .085" and also use a weighted carrier and the rifle functions flawlessly. There is so much gas dwell with this length barrel that instead of going with a custom tube you may want to start with a smaller gas port or modify the gas block to vent the excess gas.
Great reply thanks. I have a 29 inch bartlein Remington varmint contour that is begging me to build a 28 inch out of it. Also thought I would start with .076. I have reamers every .003 up to .088 and an adjustable gas block. Do you think I need to ad weiht to the carrier or get a heavy buffer? Thanks again.
Interested in this also. I have been looking at the same thing, I 26" 6.5 CM with longer gas system and adjustable block. Maybe this would save from headstamp swipes? Any more input would be great.
No not yet. Waiting on a barrel blank. I am going to build it 26" finished length. DPMS style Large frame AR.
Ok keep us posted. I just ordered the white oak 17.17 inch gas tube and a .875 gas block. Its going on a bartlein 5r Remington varmint contour and think I will finish it at 26 or 28 inches undecided for now. Also plan on doing the 60 degree chamfer for reliable feeding.
I have a 26" 223 Douglas barrel, and love it! Barrel at the extension is the biggest ive ever seen, i bet its 1.25". It steps down just infront of the gas block but whats funny is the barrel nut was fit and then the extension was screwed on so i cant remove the barrel nut. But its a shooter.
Whether or not you need a heavy buffer or carrier weight depends on the type of shooting you want to do with the platform. My original purpose in building the rifle was to take accuracy to the limit of the AR design with no regard to weight. To that end the rifle is extremely accurate with 10 round groups at 300 yds averaging 2 inches or less consistently. However, the rifle is built with a steel upper, purpose designed barrel nut, and 18 LV contour Krieger with a total weight with bipod, optics/mount, and sling at about 20 lbs. Not fun for carrying around but I have shot a couple of full blown matches with it none the less. The other option is to go the JP low weight carrier group and tailor the recoil spring as has been described in other threads for a specific load. Note that this method will yield the lightest weight rifle, but will likely sacrifice the ability to fire any and all weight projectiles for the caliber without either extra carrier velocity with heavier bullets or not enough carrier velocity to cycle the action with lighter bullets. This of course assumes no change in the amount of gas being vented. By the way, .076" is where I started with the port moved forward and should be a good starting point for you with a standard rifle length tube. in addition, if you desire to push the velocity, I would bush the bolt and turn the firing pin down to .059" otherwise you will likely pop primers ( I know from experience). I can give specific instructions if you need them.
