So I have a Surefire M300C mounted on my rifle with an SR07 tape switch. I went to the range yesterday, and when I got home, it would not turn on. I figured the switch may have been hit by while riding in the case, so the battery might have drained.

No biggie, time to change out the battery. When I unscrewed the tail cap and tried to remove the battery, it wouldn't come out! I tried hitting the stock on the ground to let inertia work it loose, but it didn't budge. I then tried touching it with a fired casing, and when it lit up. So I screwed the tail cap on and reattached the pressure switch and it worked!

Question, what could have caused it to not work prior to removing the tail cap? Also, what could cause the battery to remain stuck in the body of the light? How do you get it out?

I'm using Surefire batteries FYI

Not sure about the normal scout lights, but I have a couple of the V model lights and the batteries are changed from taking the head off, not the tail cap.

andddddd that's why I should have read the directions. I'm an idiot. THANK YOU!

Any reason why it stopped working though?

No idea.  I would have guessed it was the tape switch because that's usually the weak link in that system.  But if it's working good now I'd just roll with it.

Tape switch was depressed in the vehicle. Battery was drained. User error led to inability to remove the battery. Replace the battery, and next time you transport the weapon, un-screw the tail cap enough to "disable" the light.

Ya, That's what I plan on doing from now on to ensure the pressure switch doesn't get hit in my case. Actually the same battery is still in the light right now. It is still going strong, and did not deplete. Which has me scratching my head on why it didn't work when I hit the tape switch. I even made sure the tail cap was tight and tried it again. Since it still didn't work, that's what led me to believe that the battery got drained in my case and why I attempted to replace the battery in the first place.

Since the battery didn't deplete, any idea what could have caused the Surefire to stop working?

From what I have read on other scout lights (I've only used the M600U) they usually have a function to lockout accidental activation. Is it possible this was activated, and when you put the tail cap back on, you reactivated the ability to use the tape switch?

Like I said, my only hands on experience was with the M600 Ultra's, I was researching for a new light and came across the lockout feature.

Check your tailcap spring where the battery engages the tailcap.  If you twist on and off the tailcap a lot the spring can "wind down" around the base, essentially becoming shorter.  I had to completely unwind it and re-wind it to make sure it has proper "push" tension.  Kind of hard to explain.

Definitely wasn't the lockout feature, so kind of puzzling on what it could be

That's a possibility for sure! I'm going to check it out when I get home and see if i can wind it out a little for more tension. Thanks for the idea! I don't normally take mine off, but one of my friends has to touch everything. He definitely unscrewed it a couple times because he just had to see the battery in there. Maybe that cause the spring to shorten