Gas Tube Confusion on Brownells Barrel

[Gray05]

So, I got my Brownells 16" mid length gas barrel in.

 

Just to double check, I measure the length to the gas port. It looks like it's close to 10".

 

However, gas tubes seem to not follow the rules... like this tube. http://www.brownells.com/rifle-parts/gas-system-parts/gas-tubes/melonite-coated-gas-tube-carbine-sku100008577-44888-100402.aspx

 

Listed as carbine length but it says it's 9 3/4" which is what it would seem I need.

 

Trying to get some references to clarify the issue for myself, I found http://cheaperthandirt.com/blog/?p=330. Which would match what the barrel would imply.

 

What the hell tube do I get? Am I measuring the length right?

[shibiwan]

The gas tube has to extend beyond the barrel extension by 1.25" or so, because the tube goes into the gas key on the BCG. Get the 11.75" midlength and you will be fine.

Edited March 6, 2014 by shibiwan

[Gray05]

Thanks. I've never put one together so I wasn't sure how much extra was required.

308ar.com saves the day again.