ecoeco 223 5.56mm Laser Bore Sight, AR-15 Pistol Rifle Laser Sight Red Dot Laser Boresighter .22 .223 5.56mm Rem Gauge with 2 Sets of Batteries (1PC)

Got the .223 size and it works great. Great low price and accurate. Marked the exterior of the laser bore sight casing with a felt tip marker and rotated the laser bore sight to 4 different locations in the chamber, rotating each time 90 degrees and gently closing the bolt to hold it in place in the chamber. The laser beam spot at 50 yards was the same for all 4 locations, using the attached sighted in scope. The laser is plenty bright if used in low light conditions or indoors. At 50 yards the beam is only a few inches in diameter. Best price and highly recommended. It will make it easy to replace my old scope with the new one I just bought.

This bore sight works well enough, but the included batteries are poor. They only provided visible LED light for seven or eight minutes, which was ok, but the light was only full brightness for about the first three or four minutes of that.After then, the LED faded to be technically visible but not much use for bore sighting unless you do it at midnight on a moonless night.

When inserting the LR41 button cells you'll find that the laser can/will illuminate after the second cell isinserted as well as after inserting the third cell without the cap being screwed on. This is due to the lack of a shield to prevent the positive pole of the cells touching the body of the bore sight. This means that you'll be fumbling trying to load/unload the cells in between uses on the range

quality could be a little better. the threads for the battery compartment were kind rough

Loved this bore sight! Great price. The only thing I found that kept it from getting 5 stars was the fact that there was no way of turning it off unless removing batteries. Once batteries were installed, laser was automatically turned on and no way of turning off when not needed to be turned on, so once my optics were sighted in, removed from chamber, I had to remove batteries to store the laser.

This fit well in the chamber and felt sturdy in the hand. The light emitted was very bright and vibrant; easy to see from far away in daylight. The batteries were well organized and you get 2 sets of them.

Some of them don't fit in my gun. And need an easier way to turn laser off

after you put your "optic device" on and it's positioned for proper eye relief...put the batteries in and it will light up as soon as the batteries are in and the cover is screwed on.just put it in like it is a round and slowly ride the charging handle (mine is a .223) until seated.after that you can easily adjust your elevation & azimuth so that the reticle or dot are centered on the dot from the boresight.