My kit shipped yesterday so I have'nt built an AR yet.  So anyhoo, I'm at Lowe's yesterday and bought a can of DuPont Performance, Pure Silicon Lubricant.  The only reason I grabbed it is because it says "PTFE" on it and I'm pretty sure I've heard people mention PTFE on the board.

So is this stuff usefull for something AR related? Or did I just by an expensive can of WD-40?

just use CLP. its made for guns.

PTFE is teflon.  Break Free CLP has PTFE also.  I've never used silicon based lube on a rifle.  Maybe someone who has can chime in.

BreakfreeCLP,

What straight lube lacks is the cleaning properties of CLP (the C part).  On the ar-15, since the barrel/gas tube blows fouling directly into the action, the cleaning part of the lube keeps the rifle/fouling from gumming up and causing the action to short cycle (read Jam).

Point black, as long as the the fouling is kept fluid, the rifle will run (just way on the slimy side).

I bught both the spray and bottle of what you have. It has out performed most everything else I have tried so far. I don't use clp for cleaning, I use hoppe's #9 regular. This blue bottle stuff is advertised as dry but really leaves a waxy surface, it doesn't seem to burn off as a lot of other lubes but melts when things really heat up keeping things moving freely. I put it real heavy and wait for the carrier liquid to evaperate then wipe away the excess yellow waxy residue. I'm planning on testing it a bit more but things look good so far. By the way the only clp Ive tested so far is rem oil and it burned off to quickly.  EDITED to say I,m using the blue bottle stuff (teflon) and not the silicone stuff.