M2 tailcap hard to turn....

[**DONOTDELETE**]

Recently purchased Surefire M2, great light, but real hard to turn the tailcap. It was clean and lubed, but I couldn't operate it one handed like my 6P. I assume it's part of what makes it waterproof with the tight fit on the o-ring. Not being worried about it being waterproof, I took the tailcap off, removed the larger o-ring, and put the small one in the forward position (closest to bezel). Turns much easier, and better suits its purpose for my work. What a cool flashlight. Anyone else try this or experiment with different o-rings on different lights?

 

[lightlover]

Hi, mtb, welcome aboard

I've also found the M2 and M3 tailcaps are both *quite difficult* to turn in a one handed grip. Yes, I believe that is to guarantee them waterproof to 10m. The tight O rings help to assure that.
(For waterproofing guaranteed to 33m, you have to special order an "N certified" model. I wonder what those tailcap torque requirements are ?)

Since SF Policy is to understate every performance claim, waterproofness to 10m is certain beyond doubt. Stuart@surefire once posted on SFDB that the failure rate for the non-N Millennium models waterproofing was about 1 in 5,000, or a similar micro-percentage.

Since the M-series are actually Special Forces lights, they really are designed to be used Tactically, that is, in short bursts. So the push button is there for that, and allows easy one-handed operation, correctly orientated. The SureFire lights do have their quirks. I suppose the tailcap operation's just one of them.

I know that the design is particularly refined regarding the O ring clearances and sizings, so I wouldn't alter too much. Removing an O ring must certainly compromise the waterproofing.

lightlover

 

[SurefireM6]

I think they also use dampening grease on the tailcap to control movement. I personally love the dampening effect. On the 6P, the cap turns so easily that sometimes it will turn by rubbing on my pants. Not with the M2/M3/M4/M6. I've been meaning to get some similar grease to use on all my lights.

If you want easier movement, try a different grease without any dampening effect...something slippery.