Lock-N-Load Headspace Kit With Body - The five bushings that come with the L-N-L Headspace Gauge provide the ability to check most bottleneck cases from .17 Rem through the belted magnums. Ackley Improved chambers use the same bushing size as the parent case. - Body with 5 Bushing Set - A.330 B.350 C.375 D.400 E.420