Hornady Lock-N-Load Head Space Gauge w/ 5 Bushings. A great reloading tool for extending the life of your brass the Headspace Gauge measures variations in your casing before and after firing allowing you to adjust for the deformations that can occur under the extreme heat and pressure of a rifle discharge. This valuable piece of Hornady reloading equipment attaches to a pair of calipers using a thumbscrew and allows you to check most bottleneck casings. Hornady has included five bushings in the Hornady LNL Headspace Gauge ranging from .330 to .420 so you can accurately assess all sorts of casings. To improve your casings' longevity safety and accuracy compare and assess them using the Hornady Lock-N-Load Head Space Gauge. Specifications for Hornady Lock-N-Load Brass Headspace Gauge: Calibers: Bushings for .330 .350 .375 .400 and .420 Features of Hornady LNL Casing Headspace Measure: Compare brass before and after firing or re-sizing Attaches to calipers with thumbscrew Includes five bushings for different calibers Checks most bottleneck cases Package Contents: Hornady Lock-N-Load Headspace Gauge HK66 Hornady Lock-N-Load Headspace Gauge With Five Bushings