P2M in-Chamber Boresight with Red Laser

I have used a couple of these laser bore sight tools and this one works just like the others. First off, you need to chamber it manually. Lock the bolt back and place it in the chamber by hand. Slowly release the bolt to touch it. It is a laser and you cannot expect to put it in a magazine and load it that way. That will destroy any brand of laser bore sight tools. There is no switch to turn it on or off. Having batteries in it causes it to be on.Remove it with caution as well. These are as delicate as a laser pointer would be. (don't eject it like you would a regular round) This could mean locking the bolt back and shaking it out manually.I find that these are excellent for setting windage. They get you right on target. The elevation is a different story. I suppose at a specific yardage it would be perfect but I have found that it just "gets you on the paper" and you can manually adjust the elevation by trial and error after you remove the tool. I really do like to be able to quickly get the windage perfect though.These are relatively cheap and if you know how to chamber it without damaging it they are easy enough to use. I used it to setup a red/green dot optic. I changed the optic to green and that helped me to get it setup. (red would have been confusing)I put mine in a ziplock bag and kept the packaging that the batteries came in. I threw in a roll of electrical tape and I put tape on the battery packaging to keep them in place. I don't want the batteries to somehow discharge when I'm not using them. The entire ziplock is in my range bag if I need it.To be honest, I really wouldn't need this tool to setup my red dot. It does make it a little easier though and I know for sure that the windage is dead on when I am done. I was borrowing one of these from a friend and for the price this is so much easier than borrowing one each time I need it. They say if you borrow something more than twice you should just buy you own. I did that I bought this tool.

It works perfectly and as intended. I really enjoy the simplicity of it. But I would like to try and help others out in case they're worried about the negative reviews left for this.1- Yes, the batteries are going to go flat pretty quick. This is common for any sort of light emitting object left on for any extended amount of time, but especially for this kind of laser. The batteries that go into this thing are TINY, and they also are not the kind I was able to find at my local store's endcap. So, do be ready for that. Since you're buying it off of Amazon, go ahead and look for 393/309/193/AG5/SG5/LR754/SR754/LR48/L750/1136SO/1137SO batteries. I suggest looking for them by any of the first 4 numbers given, but any should work as long as you make sure they are, in fact, the same battery. You'll see when you get them that the batteries are incredibly small and don't hold much juice. If you plan on spending any amount of time really sighting things in, extra batteries would be a great idea.2- This does not have an on/off switch because that would provide extra bulk. It is intended to be used right away, so try and make sure to have everything set up before you pop the batteries in. This will make everything a lot smoother.3- DO be careful with how hard it is chambered in. It won't be ejected like a typical round because of its design, so try and possibly have something to help gently tap it out of the barrel on hand should it get stuck.

I bought this even though it didn't have any reviews as the little holes you see in the picture are evidence of the laser being held in place properly unlike a lot of other bore sighters out there. I took it out to the range today to help sight in my new shotgun scope for my deer gun and it performed very well. The laser is bright enough to make it to the suggested 25 yard sight-in target even on a bright day. Don't expect it to shine much further though, you aren't going to be able to see it against paper at 50 yards or even 30. It sits in the bore properly and the laser is dead center in the middle of the unit. I just had to turn it on, pop it in, and adjust my scope's elevation and windage to put the reticle over the dot and every shot when where I put the cross-hairs after that. The only drawback is that you have to remove the batteries to truly turn it off, they make too much contact even with the battery cap screwed out to its last threads. But since you probably won't be using it but once or twice a year at most, it's not a huge issue. All in all, very happy with this product for the price paid. Definitely better than more expensive and better known bore-sighters out there.

Thank you to Amazon Prime as the bore sight made it in time for a club meet where several shotguns were wearing new optics. The unit got an excellent workout and saved around 3 boxes of 12 gauge. Using a Mossberg 500, another but in 590, a Remington 870 and then 2 Benelli M4...all were easy to set-up with Red Dot sights.Conditions were partly sunny and the units red laser was visible in daylight at 30 paces. Accuracy with 00 Shot and slugs (smooth barrel if it matters) was outstanding after carefully sighting in the weapons. Only one of the scopes needed real tinkering and that was simply because of a reticle change on the Sight Mark Red Dot scope in use.The 3 supplied batteries were in constant use for minimum of 3 hours. Often the weapon(s) would sit, unloaded, at the line waiting a turn. Since the unit must be removed and batteries taken out to turn off then it remained on the entire time vs. doing that exercise repeatedly. Btw, batteries are dirt cheap and anyone would be wise to keep a spare So let's not quibble should they go dead.In short, I can't speak to the long range potential as any user will have to deal with a whole different set of variables but for getting the weapon "out of box" correctly sighted in there is simply no way you can achieve better results.