The blocks are CNC milled from a solid billit of 6061-T6 aluminum to tight tolerances for a close fit to specific cartridges, unlike the common one-size-fits-all plastic blocks.
The blocks are made in three sizes to fit most common rifle head sizes, and will hold 50 rounds.
Blocks come with stick-on rubber non-slip feet to keep them from sliding on your bench.
.338" hole size fits: 17 Rem, 17 Rem Fireball, 204 Ruger, 222 Rem, 222 Rem Mag, 223 Rem, 300 AAC.