First I apologize for necroing this ancient thread, but it kind of fits my project.
Then, lets get down to business. My concept is a pump-action shotgun with minimalistic streamlined design, with a regular synthetic semi-pistol stock and all. No pistol grips, heat shield and stuff. No accessories(possibly velcro for optional receiver side shell holder), no sling. The long barrel 1300 has a 4+1 short magazine tube, and the light is to be as short as possible while providing enough light for short distance use. Why? The barrel is to be trimmed to about 17" or slightly longer if necessary(no panic, none of this is being done in the U.S.). The light will be placed under the barrel and in front of the magazine tube, so the gun will have no unnecessary bulges and extensions and its external dimensions will be very close to the 18" 8+1 Winchester Defender. That's how I think a shotgun should be like, unless it's operated by a SWAT team member.
The power source format is CR123A and 18350 compatible.
My current plan is to use the Convoy S2 short "18350 version" as a host. It's compatible with the mentioned cell types. The fluorescent front ring will be removed as undesirable in this application. Probably with the XM-L2 LED.
For the driver, I'm going to use a generic 1,4 A 7135 based single mode PCB. This will allow for nearly half an hour of use with an IMR cell. 2,8 amp driver would be overkill both because of current drain and too much sudden, unnecessary bright light in darkness. I however think the light should be somewhat blinding(disorienting at least) to someone standing on the customer side, so significantly less than that might no be enough.
Light will only be operated by a remote pressure switch. For such, I will pick the best one out of what I already have and the soon-to-arrive generic versions and wire it inside the S2 tailcap.
My battery options are going to be primarily 18350 AW IMR, and secondarily CR123A lithium single-use. Because this is sort of
mission critical, protected batteries are unsuitable.
There is also a firearms specific problem, as I think lights and their remote switches are not perfectly suitable for pump action, but IMO pump action is otherwise preferred. This will be extensively tested to see how it suits me. It would be so much easier if my choice was O/U or automatic, but pump action is how I learned this stuff, so that's my choice for use in a potential emergency situation.
Shotguns can be destructive on lights and require a different level of durability. 7.62 (308) guns also require a more robust light.
That's important. I have already pretty much figured out my concept, but this is an interesting subject to discuss anyway. What technical details and solutions are the most important when doing a DIY or customised build for a high recoil weapon light?
Careful tightening and thread locking, high quality soldering, good thermal connection etc. Maybe epoxying components to the PCB?
A weapon-light is too important to mess around with. Your best bet is to get a dedicated one specifically designed for that purpose and proven to actually work as designed. I'd leave off every new model, and go for one of the older weapon-light designs from either SureFire or Streamlight.
That's what I would give as advice to anybody asking. Just as I would refer anyone to see a doctor when asking a very basic medical question that I
could answer myself, but wouldn't
However, I tend to trust my own design and work even more than those respected brands. Even more so, because as a (currently) civilian I'm not dealing with law enforcement limitations and liabilities. The aim here is to make something that will be exhaustively tested in recreational shooting and then adopted as an accessory to a home defense weapon. Another factor is that to my knowledge no solution exists that would satisfy my specification.
This is what I'm planning at the moment. I have also considered(and for now, abandoned) the idea of mounting on the front grip and even omitting the remote switch. The preferred form and function is because this is not purely home defense specific, even if that is the gun's primary purpose. My shotgun with light must fit in a scabbard as well as an ordinary, unaccessorized version would fit, which pretty much rules out any rail attachment systems etc. A simple clamp will be used to tie the flashlight tube to the barrel.
