I'm looking for opinions on whether to get the surefire 6 volt weapon light (951) or 9 volt (961)?  Does the increased lumens and run time compensate for the extra weight? It's for my M4.  Thanks

I dont find my 9v 962 unreasonably heavy at all....and it has good center focus for those longer range across-the-parking lot light-ups, and a nice medium bright outer ring for making a room come alive.

Weight is a serious consideration when considering point to point maneuverability and the distance you have to lug the thing. The light output of the 6 volt was adequate for me. Do some multiple target drills on a timer with your rig with all the bells and whistles, then lighten it up a bit and try it again. You will most likely see a difference ( in speed )in your target to target acquisition.

BOTH!

I've just order a 950 classic.  I can remove 1 section and convert it to a 650.

So I've got a choice of 6V or 9V depending on my requirements.

Remember you'll need to change Lamp Assemblies when you change batteries numbers.

P60/P61 for 6V (two SF123A's or one SF223AC)

P90/P91 for 9V (three SF123A's or one SF323AC)

This is very important to take care of when changing from 6V to 9V because the bulb could explode.

Al

I am a big fan of the 9V doing everything the 6V can do better.  In terms of weight, cost, and batteries, doubling the light output is definately worth it.

Also, the 9V lamps just seem to light up a car interior better, completely, through the windshield.  I use 9V exclusively, save for an A2, which is 6V and without peer.

Weight is only part of the handiness equation.  The distance of the weight from the center of gravity (moment arm, I think) is significant, so just mount the 9V light further back, so the front lens would be at the same place as if it was only 6V.