Bullet Inserts for your Modular Headspace Comparator ***Requires Modular Headspace Comparator Body*** The Modular Headspace Body must be purchased separately and can be found at the Modular Headspace Comparator Body page. Why are you measuring a single point on the bullets ogive like all other bullet comparators do? This unique bullet comparator uses a 3.0 degree ""lead angle"" to contact your bullet's ogive in the exact same location as your barrel does, giving you the most accurate and useful measurements. For example, the 6.5mm Bullet Insert starts at a .266"" diameter and angles down at 3.0 degrees to .256"" diameter, exa Mfg: Short Action Customs