Sightmark SM39021 Boresight Red Laser 22 LR Brass Chamber-Mount

The Sightmark SM39021 Boresight is a chamber-mounted red laser boresighter purpose-built for .22 LR rimfire rifles and pistols. Machined from brass to match the dimensions of a standard .22 LR cartridge, the unit drops into the chamber just like a live round and projects a red laser dot downrange so shooters can quickly align a scope, red dot, or iron sights without burning through a box of ammunition. It is an ideal zeroing tool for hunters, competitive shooters, and law enforcement who need fast, repeatable optic alignment.

Power is supplied by an external battery pack using two AAA batteries (included), keeping the laser body compact and lightweight while delivering a consistent aiming reference. The boresighter ships with a carrying case to protect the brass body and accessories during transport and storage, making it easy to toss into a range bag or gunsmith's kit.

Setup is straightforward: clear the firearm, insert the SM39021 into the chamber, switch on the laser, and adjust your optic until the reticle and laser dot are co-aligned. This dramatically reduces wasted cartridges and shells during the sighting-in process. Brand: Sightmark. Model: Boresight. MPN: SM39021. UPC: 810119014528.

Your purchase includes:

• Sightmark SM39021 Red Laser Boresight for 22 LR (brass body)
• External battery pack with 2 AAA batteries
• Carrying case
• Instructions