Switch compatibility - SureFire vs Solarforce?

[thejrod]

I assumed Solarforce switches/tailcaps were interchangeable with SureFires.... perhaps this assumption was wrong.
I took my Solarforce L2T switch and put it on my M957 Weaponlight, wanting to get rid of the standard SureFire tape switch and replace it with a clicky (that didn't cost $45). Didn't work. It threaded on fine, but the light wouldn't work.

Maybe they're only compatible with SureFire P and C series, but not the M series?

Do I have any other options for a replacement M series switch in the price range of the Solarforce?
Has anyone tried modifying the standard SureFire tapeswitch into a clicky?

 

[RI Chevy]

I have interchanged several Solarforce tailcaps on both my 6P and 9P without any issues at all. Just be sure that the spring is making contact with the bottom of the battery. You may need to use a small magnet to accomplish this. Any photos to help us better understand what you are using?

 

[TMedina]

You're sure it's a Surefire M957?

 

[thejrod]

You're sure it's a Surefire M957?

Type - it's an M97.
Thumb screw weaponlight, 3 cell, turbohead, tapeswitch.

 

[Erzengel]

A too short/weak spring might be the issue. Please check if there is a gap between the tailcap and the main body. If there is no gap it might be possible that the switch doesn't screw fully down and therefore it can't make contact with the end of the tube. In this it might help to shorten the tailcap or to remove the anodization on the threads.

 

[HotWire]

I'm looking at two bored SureFire 9P lights. One has a Solar Force twisty, the other a SureFire twisty. The switches are interchangeable on these two lights. I would clean all contacts and carefully stretch the spring a little. Why two different kinds of caps? One light has a more powerful incandescent bulb than the other. It's easy to grab the one I need.