OP are you using this on a pistol rifle or both? In any event this NC light will fail and at 150 supposed lumens is in my opinion far to dim for a weapon light.
I will strongly suggest two different weapon lights one for a long gun the other for a pistol.
The long gun light-Fenix TK32. This light was specifically designed to be mounted on a long gun. It has 4 output modes, a remote pressure switch and on high has an amazing range of 400 meters you cant miss with this light.
Second light I highly recommend is the Olight PL-1 Valkyrie for your pistol. It is only $99 but is easily mounted on a picatinny rail, cranks 400 lumens off of 1xCR123. The light also has ambidextrous controls. Ive got some good experience with Surefire pistol lights and they all pale in comparison of the Olight. The Olight is super easy to attach and remove, its ambidextrous switch makes activation 2nd nature and at close ranges 400 lumens is more than enough.
I have yet to fire a pistol with a Surfire light that wasnt a pain in the *** to turn on IF it turned on at all.
The TK32 is going to be the more expensive of the two lights but is about as close to a perfect light for a long gun that there is. From AR-15's to semi auto 12 gauges the TK32 doesnt fail and puts out a huge beam with a concentrated hot spot to put onto targets hundreds of meters away. Good luck
