I must say that my LHBS guy was a real a$$munch when I went in to get the materials to construct this beauty. I told him I wanted 7ft of beerline, and he asked, "What for?" I said it was for bottling homebrew, and he told me that I needed 5 feet.
I told him that it was for a homemade beer gun, and he rattled off some numbers, saying, "So this guy says that you're gonna push 5psi through 7 feet of line at blah blah blah..." I said yep, and that dozens of people had built it exactly the same way, and that it reportedly worked great.
Finally, I asked, "Are you going to sell me what I want, or am I gonna have to go elsewhere?" The guy responded, "Well, the guy who gave you the instructions is an idiot, but I'll sell it to you."
For the record, I built it exactly as instructed, and it worked great (excepting that I actually needed a drilled #3 for the larger PET bottles). Thanks, BM, for being a Biermunch, and not as I said, an a$$munch like the guy at my LHBS.