Lots of choices here and I own a total of four, which sometimes does not work in my favor. I have two Bushnels, one BSA and a LazerLyte. The BSA, has the most mandrels that even go up to a shotgun bore and my .50M/L's.
My lazerLyte is mostly used on my handguns. Now, a friend of mine who probabaly owns more bore-sighters than I, really likes his Leupold.......
Other line members will be by shortly and post their preference. ....
Be Safe !!!