buddy has one and i played alot with it. here is what it did for me. i can buy hp's so thats not a big deal to me. i think in 22s velocity is the main factor in expansion not hp shape. now we all know that just minor differences in bullet shape can effect accuracy alot. thats where it shines. back in the day i bought 22s by the case. all different bands and types. noe when i say bought a case of blazers, they might shoot great in a couple gun and not so great in a coupe more. with the tool i could experiment enough to make about any ammo do as good as the best factory ammo. so why didnt i buy one? because mostbly 22s are just plinking stuff for me and a 1/8 in better group doesnt matter much to me and using it is more work then i was willing to put into it.