Surefire L1/A2 O-Rings

I've had two sets of replacement tail-cap o-rings for the A2/L1 sent to me and they seem too small. Surefire confirmed the part number so they resent them just in case their shipping guy grabbed the wrong part. I finally tried them out and my tail-caps spin like butter now. I had to stretch them on but things seem ok once they were in place. Any one else notice this?

Right: Original Left: New


Right: Original Left: New


Outside: Original Inside: New


A2 w/ New o-ring


L1 w/ New o-ring

Same issue with Surefire M6 O-rings, I've bought replacement O-rings for Surefire E and C series from lighthound many times, they've always worked well. But When I bought a set of "Surefire M O-rings" they were frustratingly small for both the head and tail. They do however fit wonderfully on my M3, leading me to make a silly thread called "is M6 part of Surefire's M series." I left out the O-ring part in the title accidentally, and consequently incurred a hilarious outcome:shrug:

When I asked Surefire for replacement O-rings I was sent a pair that seemed to be correct. The bezel was correct [thank goodness, cuz the existing one is beginning to crack] but the tail was about a third thicker as the existing o-ring on the body [there are two slots total], I got it to fit but then the tailcap was so snug that every time I turned it the lube stripped off the o-ring leaving it bone dry. I often worry that repeated turns will eventually destroy it so I left the TC on momentary on.

Thanks good thinking of you, I don't know what happened to my invoice, its probably still taped to the side of the box that was tossed out:thinking:

My o-rings were nice and smooth for about a day and now things are too tight. The o-rings must have expanded. I'm going to try the ones Lighthound has:
http://www.lighthound.com/O-Ring--SureFire-A-L-Series-Tailcap-o-ring_p_1358.html

Funny thing is that my 4-sided A2 has always been really smooth and easy to turn while my round A2 and my L1 are always stiff. I swapped things around and it's the tailcap. The tolerances must be a little different on the older tailcap.

M6 O-rings are 1 3/8 ID X 1 1/2 OD. They can be found in most hardware stores.