DTOM, it just loosened up on me. I thought I had it locked down tight, and it more than likely was, but the recoil loosened it up. Loctite would have done just fine, I just wanted something I could switch locations with until I figured out what worked for me.
Az, I've got a 250 lumen on mine, been running that for at least a year and a half now - probably closer to two. It's BRIGHT. My light has a bigger head than the 6P, with a deeper reflector assembly - throws the 250 lumens out far. As in sight on a target and hit at 400. I got the idea from my best friend - he used a Surefire with extremely similar stats while in the sandbox. He said quarter-mile shots weren't hard at night....... he was right.
Tac, I didn't like the light at 6 o'clock. Just seemed to be limited, as I was trying to use whatever I could as a natural rest - or down in the dirt in a prone position. So I wound up running it at 3 o'clock, and all the way forward. Makes it more difficult for me to activate accidentally...... got jumped for a "light AD" at one point, so that ain't happening again ;-) It's not the best in the world answer, but it's what I came up with that seems to be the least worst answer. At least for me.