I always HATE, HATE, HATED having my shotgun getting hung up on things. Trees, bushes, doorframes, even my own gear. Drove me crazy! So, I built my own light that won't. First, I had to find a flat magazine cap that fit the 590 Shockwave. Here's my thread about it: http://mossbergowners.com/forum/index.php?threads/mossberg-magazine-cap-options.18960/#post-266544 Took a little filing on the end of the magazine tube to get it to fully seat, but it works. This gave me a flat surface to work with. Now, to find a tiny light. Obviously, I searched ebay, Amazon, Wish, etc for small lights. I quickly realized that most were designed around either AA or AAA batteries, which immediately made them all too long. And you can forget about coin batteries, right? But then I remembered a small combination laser/flashlight a friend bought on ebay that uses a cr123a battery! Imagine cutting an AA battery in half like a tootsie roll. They're small, and rechargeable! The rechargeable feature turned a corner for me. See, I have 4 sons, all grown now. They're outdoorsman like me. I remember seeing them plug in these little black headband lights, so I asked them to bring a few over for me to look at. And then my son Dan said, "These are OK, dad, but nowhere NEAR as tough and small as our mountain bike lights". Now, I've seen some hellacious videos of my sons downhilling here in the Adirondacks. I've been in combat, and some of their gopro vids made me pucker!! And their lights still work! Theirs are all so beat up, you can't even see what brand they are. My son's use them in the rain and snow, too. Crazy, like dad! They are tiny. They are light. They are even rechargeable! AND. THEY. ARE. TOUGH! BINGO! They come in all shapes and sizes, are specifically designed to take a beating, and have lots of mounting options. I should be able to find a small round one that I can attach to my magazine cap. So, I bought 10 different ones! They're in shipping now. I'll report back when I've played with them enough to get some ideas. If I were to build one from scratch, it would have these features: 1. Uses a single cr123a battery, layed over on it's side to make it short. 2. Rechargeable. 3. Click the lense to turn it on. 4. Machined aluminum housing. Here's the 1st one, a $17 rechargeable bike headlight and taillight set: http://www.walmart.com/ip/Bike-Ligh...Taillight-Smart-Bicycle-Phone-Mount/895362929 It's an aluminum light that screws into an aluminum base, that pops into a rubber housing. I'll let the pics speak for the rest, but it came out great, is tough, waterproof, light, and rechargeable.