FieldSport 6.5 Grendel Laser Bore Sighter Boresighter for AR15 Grendel, Auuminum Red Finish

Pretty straightforward to use, make sure you remove the bolt carrier or leave an empty magazine in to keep the bolt from slamming closed on it or it might get a little stuck. Just used it in the house at ~19yards (according to my rangefinder), we'll see how close it gets me when I make it to the range. Give 4 stars overall because battery life was terrible, laser got noticeably dim after ~7minutes total use, if I order one again I'll get additional batteries. I'll try to update after a trip to the range.

Let me start by stating that at this time, this is the only Grendel bore sight that I could find.I was really torn between 3 and 4 stars because there is one major problem with the device.The manual states to NOT close the bolt on the bore sighter as the extractor may damage it. Since you cannot close the bolt, the bore sighter is loose in the chamber and can even fall out. Consequently, the 3 star rating.However, although it doesn’t state it on the product page, in the manual it states that the only purpose of the bore sighter is to “get you onto the paper”. That it does. My scope was waaaayy off to the left and this let me bring it approx. to center horizontal. It was also a bit high and it allowed me to adjust approx. to center vertical. I keep saying approximately because I would push the bore sighter “tight” into the chamber with the eraser side of a pencil to get a more accurate bead. Unfortunately, the laser kept jumping up and down as I pushed. Therefore, the 4 star rating for doing what it is designed for — getting you on the paper.This device needs a sturdier case, perhaps not aluminum, that you can close the bolt on and eject. It would also benefit from some slim o-rings to center it in the chamber — even if you have to push it out with a cleaning rod.One thing I do like is that the laser is always on. Some of my other bore sights only light when you “dry fire” them and they take a lot longer to zero. The manual highly discourages dry firing this bore sight as it may incur “significant damage”.

Unlike the other reviewers, I was able to chamber the bore sight to keep it in place. The instructions say not to, but it didn't cause any problems when I did it gently.My only complaint is that there is no on/off switch, so you have to remove the batteries when you aren't using it to turn off the laser. Other than that, it made it easy to quickly get a rough zero.

Worked like it should, once I finally got it to stay on anyways. I was sighting two rifles and with the first I kept trying to secure the bore sight with the bolt which would cause the laser to shut off. Finally got it to stay on then on the next rifle after screwing with it for 10 minutes I locked the bolt back and the bore sight stayed in place. Not how I would prefer to do it but it worked.

Product delivered as advertised. Instructions included were not specific or correct for this item. This item requires (2) batteries (included), instructions say (3) are required. Instructions say to load batteries and screw end plate down to turn on. This item is too short to load the batteries and still not turn the laser on. You have to leave the batteries out until you are ready to use the item. The 6.5 Grendel probably shorter than some other designs, and the instructions are written for inclusion in other products. Product works, just not as simple as expected.

Couldn't even hit paper after bore site. Had to be guided by range employee and finally was able to get on paper

Works as intended.

Fitment isn't great, turning on/off stinks. It will save you ammo, just expected more