LR308 gas tube length?

I'm in the middle of assembling my first LR308 build. I've got the upper assembled and went to drop in the BCG and realized that the gas tube is about 1/4" or so too long. The tube is rifle length from Brownells, the barrel is 20", and I'm using a Troy low-profile gas block. The Brownells tube measures 15-1/8" overall. If this is wrong, why is it sold as a rifle length?


I'm an idiot! It's the right tube.