>>64374285 (OP)
>What's the consensus on these, waste of money or useful tool?
This is purely and objectively a matter of numbers anon. The point of a bore laser is to get you on paper, at 100yd even, the first shot, even if for guns where visual bore sighting is annoying/impossible. Even if you're on your own rough land so that it's challenging to spot misses. It's direct savings of some number of bullets.
So how often are you rezeroing from scratch? How many rounds does it normally take you otherwise? What's the cost per round? When you add that all up is it more than the cost of the bore laser, yes or no? That's all there is to it. If you've got a ton of guns, are shooting expensive rounds, don't have the best zeroing spot, and/or for whatever reason you tend to shift around optics a fair amount (jumping back and forth between vis and thermal say) and don't want to spend the $$$$ for multiple zero-holding Spuhr qd rings or shit like that, bore laser will easily pay for itself. Or if you've made a small business of it or side bit to your gun smith business and are zeroing other people's guns regularly and you charge for it. Again, literally paying for itself and then some, you might even want some fancier magnetic thing.
If you're one dude with a rifle or two that you take apart basically never then nah.
