CVLIFEBore Sight Laser 223 5.56mm/9mm/.243.308/12Gauge/7.62x39mm/.45acp Red Laser Bore Sighter with Batteries

I purchased this laser bore sight for use in several 9mm pistols I own. I started off by trying it in my $1,000 Springfield EMP4 CCC 1911. Heeding warnings I'd seen about laser bore-sights in the past I was VERY careful not to let the slide "slam home" on the bore-sight. But, despite inserting this laser bore-sight into the barrel and gently returning the slide to home position the bore-sight JAMMED into the barrel. Using a cleaning push-rod to attempt to push it back out from the muzzle end did not work. It was stuck in there like cement. I ended up having to completely field-strip the 1911 and punch the bore-sight out using a long pin-punch and a steel armorer's hammer. There's no way I'm about to insert this into any of my nearly $200 Glock barrels, so I will be sending this thing back for a refund.

Edit: Updating to a 1 star. Didnt last an hour with batteries that came with it. Ok no big deal. Bought name brand batteries to replace it. they went out in 20 minutes. Put in another new set they went out within seconds. The batteries are good. Tested with a voltage meter. The electronics must be faulty. I can explain it any other way. Beware.Other lasers will have a quick method to turn the laser off, either a button switch or you can unscrew the cap slightly. This laser cap needs to be COMPLETELY removed and all the batteries removed. even with 2 batteries in it, there is enough voltage to fire. Not a dealbreaker but its two extra steps EVERY time you want to use it. Put batteries in. Take batteries out.Secondly, the beam is a line not a dot. While diode laser technology does actually form a line vs a dot, most lasers will have a lens that focuses the diode light down into a point. This one you can see the line even at a distance of an inch or two. I needed this to show a dot over a few feet and it is hard to find that exact center. For sighting a gun it might work, but not for my alignment application.I bought it for the small form factor to fit in a bore. I'm out 12 dollars, no big deal

Since there isn't much to a laser bore sight, I figured I'd give this more cost effective model out; it turns out to exactly what it claims to in the description. I used this in my G17 and found it very easy to feed into the barrel from the top of the slide.Couple things probably worth mentioning. First, it is true that as long as the batteries are in the device, it will remain on--so take the batteries out after each use. Second, the fit inside the barrel is spot on, but it can cause the device to get stuck in the chamber. Since there is no real "lip" on the device like on the back of a 9mm casing, there is nothing for the extractor to grip, causing it to remain lodged in the barrel. If you simply grab your cleaning rod and give it a firm poke on from the other side of the barrel, it will dislodge the device. Third, this is a rather "cost effective" device, meaning you probably would be best to not slam the slide closed on it (or dry fire with it in the chamber), as this would probably damage the device.Seems to work rather well; helped me correct my rear sights that were off center a bit to the left.

Poor accuracy for greater than 7yd shooting. It's a nice little thing to help you sight your gun initially not at the range, but expect to tweak them a little as you shoot. When I removed the laser from the chamber and put it back in, my sights were left of the laser by about 3 inches at a 20ft range. That's kind of acceptable if you're shooting close, but don't expect to sight a rifle or carbine for 100yd shooting.I know it got a lot of flack for not having a button to turn off... but honestly, it's not difficult to open it and flip over a couple batteries and close it back up again. Its not like you're going to use it more than once in day while you're sighting the gun. Honestly, even if it was perfectly accurate, I wouldn't expect to use it more than once every few times I go to the range, so the extra 30s opening it, flipping two batteries and closing it up again is Not a problem.The problem, again, is that the accuracy is really not good. But for $12, what do you expect.

I should have know better just by looking at this POS. I bought this to zero a Holosun 507c for my pf940c build. The shape of this thing doesn’t allow the slide to close all the way which means the barrel stays tilted up. I didn’t realize this until after I had adjusted the turrets on my optic and now I have no way of re-zeroing it without going to the range and doing it the old fashioned way.It doesn’t go all the way into the chamber and has no groove for the extractor to clip into. This thing might work on an AR-9 or guns of that nature, but for a polymer framed, striker fire pistol it’s completely useless. I’m returning mine and emphatically telling everyone NOT TO BUY THIS WORTHLESS PIECE OF JUNK!!!

I received a lemon, the company replaced it immediately after asking for photographic proof of problem. Now it works quite well. Its not as perfect as zeroing in properly with sights, but close enuf for close range combatself-defense shooting and my intention is to use it for two things which it does well: 1] as emergency corrector if my sights get knocked off their placement, and i need an emergency method to realign because i cant get to range etc, to fire live rounds to confirm sights are re-zeroed again. And 2] to train my draw and forward press by practice aligning my barrel to target asap in the draw, for when miliseconds is critical in combat situation. You can see your barrel movements and alignment because the laser is on and "pointing" the whole time. Ie, train to get barrel and therf bullet aimed at target asap in the arm movements of the whole draw and aim cycle, rather than only once Ive begun bringing sights all the way up to my line of sight. Again, for milisecond improvementsWorks well.