Sightmark 300 BLK Laser Boresight

Manufactured by Sightmark
SKU: SM39043
MPN: SM39043
Manufactured by Sightmark
5 Reviews
$25.47 $29.97

In Stock

NOTE: Limit 3 per household. Quantities exceeding 3 will not allow checkout.

We are fully staffed and processing orders. Standard orders are shipping in approximately 1 business days or less. FFL orders take approximately 10 business days or less if you can provide us an actively receiving FFL location. Due to high demand, there is a limit of 5 FFL items in a 30 day period.



The Chamber Laser Boresight gets you on target quickly without wasting a single round. Simply drop the boresight into your chamber like a standard cartridge, and the bright 632-650nm red laser will show you exactly where your rifle is aiming. When done, it ejects just like an empty casing, clearing your chamber allowing you to go straight to live fire, without the risks of forgetting a bore-mounted sight.

This compact laser boresight is designed to fit 300 BLK and .300 Whisper chambers, and includes carrying case, batteries, and instructions.

  • Compact and lightweight design fits in any range bag
  • Powered by (3) AG3 batteries
  • Designed to fit 300 BLK and .300 Whisper chambers
  • Tested and recommended by the National Tactical Officers Association
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Caliber Gauge300 Blackout
TypeLaser Boresight

WARNING: This Product can expose you to chemicals which is known to state of California to cause Cancer and Reproductive Harm. For more information, see

Ratings & Reviews

5 reviews

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Do not buy.

by -

This product deserves no stars. Worked for 5 minutes then the laser faded out. Changed the batteries thinking that was the problem and flashed bright for about 5 seconds then same thing. Again I changed the batteries and got the same result. 30 bucks wasted. Ended up just chunking it. Not even gonna trouble primary arms with an exchange or refund. All I ask is that you stop carrying this product. If I had done my research like I normally do I would have seen all the bad reviews elsewhere. My fault and I'll take the loss.



Joe, do you think it may have been bad batterys, just wondering.

Not a good product

by -

Look elsewhere, don't buy this one. Out of the box, at 25 yards, this laser was sighted off about 6", totally defeating the purpose of a bore sight. I haven't even bothered to try to adjust it yet, because the batteries ran down really quick as a previous review stated. I don't know if its just junk batteries that it ships with, so I ordered some name brand batteries to test with.

Do not eat a bad product


Hey Joe You should send the defective product back so PA can have a chance to make things right with you and so they can inspect the product to let the manufacturer know how to correct the defect

It works for me

by -

So many bad reviews? I have several of these SightMark bore sight lasers in other calibers and they all work perfectly well. So I took a chance and bought this one. The production date was July 2019, so it might be a newer lot with better QC. It worked just fine. I found it difficult to close the bolt and lock it in so I took the upper inserted it in the chamber and held it tight with my finger. It lite up right on my old scope zero. Changed scopes, new scope zeroed right up with no problems.