Jump to content
308AR.com Community
  • Visit Aero Precision
  • Visit Brownells
  • Visit EuroOptic
  • Visit Site
  • Visit Beachin Tactical
  • Visit Rainier Arms
  • Visit Ballistic Advantage
  • Visit Palmetto State Armory
  • Visit Cabelas
  • Visit Sportsmans Guide

Unicorn Gas Tube Needed


jtallen83

Recommended Posts

So I'm trying to build a pistol with a Sig P716 12.5 inch barrel. My measurements from the gas port tell me I need a 10 7/8 inch long gas tube to make this work and I have not seen anything close except a reference to an Armalite super SASS carbine length tube at 11 inches. I'm afraid the 11 3/4 inch for a mid-length will be too much. If anyone has a source for something close to this odd length tube please let me know. Push comes to shove I'll just have a spare barrel for my 716. On a side note the port in this barrel is .071, might help explain why my 716 has symptoms of being under gassed.

Link to comment
Share on other sites

9 minutes ago, 98Z5V said:

White Oak Armament, brother.  You'll have to call them.   309-376-2288   :thumbup:

I was just looking at their gas tube page thinking someone has to be custom making some of the lengths they sell, they will get a call Monday. Hope they can help, too nice and too cheap a barrel to give up on. The shoulder at the gas block is way off but the dimple jig makes gas block alignment foolproof. If they can make it I may have them make a few and then grab more of those $79.99 Sig barrels.

Edited by jtallen83
Link to comment
Share on other sites

@98Z5V I  used the center of the cam pin cut out in the upper to determine the 10 7/8 inch length, that should get me what I want won't it? Would I be better fudging a little to the short side then opening up the port if I need more gas? I don't want to custom order a tube only to have the tube bottom out in the carrier key.

Edited by jtallen83
Link to comment
Share on other sites

4 minutes ago, jtallen83 said:

@98Z5V I  used the center of the cam pin cut out in the upper to determine the 10 7/8 inch length, that should get me what I want won't it?

That'll be perfect.  From center of cam pin cutout, forward to gas port hole in barrel.  + one more dimension.  Pick up a standard gas tube off anything, and determine how much longer a gas tube is to it's end, after it's gas port.  Those two numbers together will give you an exact length measurement that will work like a champ.

Hold on - I have one right here - measurement coming right up.

That additional length,from gas port in the gas tube to the end of the gas tube is 0.600".  Add that to the distance of: center of cam pin cutout to center of gas port in barrel, and you'll have it perfect.  :thumbup:

Edited by 98Z5V
Link to comment
Share on other sites

These guys are fast! ordered at about 1000. Got a call to confirm the order about 1330, very good customer service, he went over exactly how I got the measurements and what I was building so he would be on the same page. At 1545 I got the tracking number! I may just get to mock this thing up before heading back to work.

Link to comment
Share on other sites

Gas tube is a perfect fit, dead center of the cutout. Just ordered the Aero 9 inch rail, hopefully the tube makes it past. Had bought a cheap rail local but the barrel nut blocked the tube from passing into the upper, had a spare nut from a MI rail and the tube just barely made it in, as long as the Aero nut doesn’t have any more meat than it I will be good. 

Next trip home I will start a build thread, CDNN still has a pile of those 12.5 inch barrels, with the SB3 “brace” you can make a nice 308 pistol about as close to a SBR as a guy can get. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...