From what I have gathered over time listening to experts and learning from experience. 60-65 lumen is minimum tactical application. For indoor use 9v 105-125 lumen works very well and has minimum reflected light from walls/furniture. It also provides the best run time, lumen ratio (when referring to Surefire 9v products). I prefer a handheld Gladius in this application personally. Outdoors in a rural area with vast open spaces, you can get away with the biggest and badest light your wife will let you buy. I think a handheld M4 from Surefire would be plenty and less on the pocketbook than the M6. An M3 with a turbo head will also help the throw on the beam over a standard M3. If it is strictly weapons mount you are considering, a 9v Surefire with a turbo head may be a good choice. Using the MN11 bulb you will get 225 lumen, and again, the extra throw of the turbo head for rural use. I hope this isn't more confusing than helpful. If you have the money, buy more than one and use them as you see fit. Otherwise, get the best all around performer for your use.