I am not an expert either but.....
.... I have carried lasers mounted on my primary weapons in combat for about 18 months and counting and.....
......I use them for my primary HD weapons, that I practice with, with some regularity. So I can tell you what it means to me and you can take it for what it is worth.
There is a difference between rifles and pistols and green and red and IR lasers and Chinese Junk and CT well... let's see, how do we sort this out?
Let's begin at the top and work our way outward eh?
This is the PEQ-15 Advanced Target Pointer Illuminator Aiming Light.
It is bad ass. You can buy an airsoft copy for $39.95. But the airsoft copy is not adjustable to 1 MOA or have an IR capability nor the 500m range. Once you zero it and lock the real deal in it is dead on target. So at night if you are sitting there with your IR laser targeting a bad guy he won't know, unless he has NVGs too. It can also send out an IR flood light, which can be useful also.
If you take the cover off you can use the red light laser in the day time.
This is not very useful outdoors during the day time.
But indoors, or in twilight... especially if you put a signature lens cover on it and get it to display a unique signature you can tell where you are aiming as opposed to your buddy, and where he is aiming too, since he will have his unique signature. But you have to actually practice this to get good at this.
You can also use this to direct aircraft to drop explosives and that could prove helpful. You just have to be careful. The laser works both ways. But draw a big enough circle and the pilot gets the idea.
Most soldiers have one of these or a similar model.
Then there are green lasers for rifles. These are useful for other reasons. You see America when you point a rifle at someone you may be committing assault. In combat, you might just be giving a helpful warning, or directing someone (not with you) to do something important. You could also be scanning your perimeter from a covered position at night. The green light serves as a warning and illuminates a much larger area than expected. If something moves it is much easier to pick up. IME Green laser are not really very accurate past 30-50 feet. Not that someone could not make an accurate one, I just don't know of any. This is also useful for flagging cars that are approaching too close, too fast or otherwise in a threatening manner. People stop very fast with a laser on their hood if their intentions are otherwise peaceable.
On shotguns the military does not normally issue lasers. I use a green light laser on mine however for HD. It is accurate at 50 feet within 3". This is plenty accurate for HD uses with 12 GA slugs. When the green light hits one of my white walls inside my house the whole room turns a pale green color. I know at room and hallway distances that if the laser is on a target it will hit the target where the laser is. This makes weapon handling much easier for me. There is no "looking" for the laser. You would have to be blind to miss it. This means I can keep my head off the stock and searching and scanning for threats and worry a lot less about aiming. Still I mount a light too. Outdoors, in bright light I can see the laser about 100' away. It lines up perfectly with the scope on my HD shotgun.
There are lots of other laser you can mount as well. For shotguns I also like the three dot lasers, that put out three red laser beams. These are useful as they print a bigger target even though it is red. They are bit heavy though.
On to the pistol...
On my M9 I have been issued a forward grip activated CT pistol red laser. Out of the box it was zeroed to the weapon at 15' and is great out to about 25 meters, which is as far as I can reliably see it in the day time. I use it in the same way I use the green one on the rifle. I also use it in low light and indoors to help with aiming.
It is slower than aiming.
But guess what, it is more accurate too. All the time we hear about how you can't miss fast enough? Well, what if you didn't have to worry about missing anymore? Would it be worth an extra half/ quarter second? While the bad guy is shooting and missing? To me, while I am wearing level 5 body armor and helmet I feel I can afford the extra half/ quarter second.
CT has the current monopoly on lasers that are grip activated. This is OK. Every CT laser I have ever used has been 100% reliable and accurate right out of the box.
On my SD hand guns (mine and the wife's) we also have CT lasers. They do help with training. But they are also accurate as hell. You train with them, you train without them. If it is important enough that you have to shoot something, than you want to hit it and not miss. Train enough and speed won't be a problem.
The rest:
The Chinese junk is junk. There are a few items out there that are interesting but most won't stand up to the recoil of real weapons and are designed for airsoft. They don't hold zero and rattle apart, even on .22 semis. It is like anything else, you pay for quality or you get left in a lurch.
