Why One Bore Sight Is Never Enough If You Own More Than One Gun
Why One Bore Sight Is Never Enough If You Own More Than One Gun
Derek served as a Marine Corps rifleman before transitioning to gunsmithing, where he specializes in optics mounting and zeroing for AR-15 platforms. He has mounted and zeroed hundreds of red dot sights across duty, competition and personal rifles.
A bore sight laser is machined to one exact chamber dimension. That precision is the entire reason it works, and it is also the reason a single bore sight quietly stops being useful the moment you own a second caliber. Anyone with more than one gun in the safe ends up needing more than one bore sight, whether they planned for it or not.
Why a Tight Fit Is the Point, Not a Limitation
A cartridge-style bore sight seats in the chamber the same way live ammunition does, which is exactly what lets it project a laser along the true bore axis. Loosen that fit to make it work across multiple calibers and you lose the precision that made it worth using in the first place. A 9mm bore sight forced into a .40 chamber, or a .223 bore sight jammed into a 5.56 chamber with slightly different tolerances, does not just fit poorly, it can genuinely damage the chamber.
There is no universal version of this tool that actually holds up. Each caliber needs its own.
What Actually Ends Up in a Working Kit
Most shooters who own more than one platform end up needing some combination of these four, whether they realize it upfront or build the collection one gun at a time.
The most common pistol chambering by a wide margin. If there is only one bore sight in the collection, this is usually it. VPDOT's version is a compact brass build at just 16g, with LR41 batteries and a reusable storage case included.
Shop the 9mm Bore Sight →Standard for AR-15 and 5.56 chambers. Anyone running an optics-ready AR platform is going to reach for this one repeatedly, not just once.
AK pattern rifles have their own case geometry, and this is the one people most often forget to buy until they already need it. VPDOT's version ships with 6 LR41 batteries for repeated sessions.
Shop the 7.62x39 Bore Sight →Easy to overlook, but CZ-82, Makarov PM and PA-63 owners deserve the same precision everyone else gets.
The Moment This Actually Pays Off
The value of having the right caliber already sitting in a range bag shows up on the day you least expect to need it. A new optic arrives, a rifle comes out of storage after a year, a sight gets swapped between two guns in an afternoon. Nobody plans a special trip just to buy a bore sight before mounting an optic, they either already have the right one or they improvise, and improvising with the wrong caliber is exactly how bore sighting mistakes happen in the first place.
A small labeled case with all four calibers turns a task people put off into something you just do the same day the optic arrives.
Frequently Asked Questions
Not one worth trusting. A universal fit sacrifices the tight chamber tolerance that gives you accurate bore-axis alignment in the first place. Caliber-specific tools remain the only reliable option.
LR41 button batteries hold up well over long storage. If the laser looks dim after months of sitting in a case, a quick swap almost always fixes it.
Yes. Every VPDOT laser cartridge does both jobs, zeroing a new optic and ongoing trigger practice at home, so it earns its place in the range bag well beyond the day it was bought.
Build Your Bore Sighting Kit
9mm, .223, 7.62x39 and 9x18 Makarov, each one precisely matched to its chamber. Zero every gun in your collection without a special trip.
Zero faster. Train smarter. Trust VPDOT.
