Both of my BCM midlength uppers have .065" ports.
They are both of the 16" flavor.
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Are you the same Carlos from down around Vancouver, WA?
I've only run across a gas tube with an undersize bore once in 20 years, lots of other gas tube problems though. Too bad you have the PF, it helps to look up inside the front sight base and make sure the hole in the FSB lines up with the hole in the gas tube and that the hole is clear and the proper size.
Last edited by Tweak; 08-15-12 at 12:16.
I went and checked the numbers and the port size should be around .076.
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BRT OPTIMUM HFCL Barrels - Hammer Forged Chrome Lined 11.5", 12.5", 14.5"
BRT OPTIMUM Barrels - 16" MPR, 14.5" MPC, 12.5" MRC, 11.5" CQB, 9" PDW
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BRT MicroPin Gas Blocks - .750" & .625"
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I've got a 14.5 middy that's running similar. I pulled the gas tube out of it yesterday and found that the end that goes into the key is about .005" smaller than a used gas tube I had on my bench.
It looks like the existing gas tube never had the bulb end on the tip of the tube where it goes into the key. And there's a lot of carbon fouling on the 3" of tube forward of the key.
I have a new tube showing up today. So I'll get to shoot the gun pretty soon. I'm not sure if that .005" is leaking so much gas that it's causing the light cycling or not...![]()
"You people have too much time on your hands." - scottryan
Are you able to see any of these characteristics on your gas tube?
"You people have too much time on your hands." - scottryan
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