They sell hard shell nut crackers but they're 50-$75...
I've used a bench top metal vise for black walnuts, I don't care much for the flavor of them though.
Hickory nuts I love, not that hard to crack with a regular nut cracker, but not easy either, tend to smash them.
Plain ole pair of vise grips works good and easy squeeze squeeze crunch crunch, but takes adjusting back and forth tightening and loosening for different sizes and turning the nut. Takes a bit to get efficient at it but nice cause it won't over crack them and leaves the nut meat whole. I use vise grips for Brazil nuts also.
I've used a bench top metal vise for black walnuts, I don't care much for the flavor of them though.
Hickory nuts I love, not that hard to crack with a regular nut cracker, but not easy either, tend to smash them.
Plain ole pair of vise grips works good and easy squeeze squeeze crunch crunch, but takes adjusting back and forth tightening and loosening for different sizes and turning the nut. Takes a bit to get efficient at it but nice cause it won't over crack them and leaves the nut meat whole. I use vise grips for Brazil nuts also.