There are two boresighters I prefer over all others. The best unit ever made so far in my opinion is the fantastic Leupold Zero Point Magnetic boresighter. The lit reticle feature isn't required, but can be useful. The magnetic boresighters do not require a target for a laser to reflect off or an arbor of the correct size to insert into a muzzle, and are every bit as accurate. Remember, a boresight is simply to get you onto paper when shooting so you can sight in with the loads you want to use at your particular distance. I use mine every time I mount a new scope, and it is also useful for checking your zero after travelling. A reasonably priced alternative is the Bushnell magnetic version, unlit, but more affordable. Remember, you only have to buy one once, and it fits all calibers and gauges.