EE - Our caliper base was design to work in conjunction with Sinclair/Hornady Comparators to measure loaded rounds. If you are measuring only projectiles to verify consistency, I would recommend measuring with just a comparator and calipers. By measuring with only the comparator, you will have greater dexterity to hold the projectile in place during the measuring process. Send me a PM if you would like further clarification.Will this work with the sinclair comparator?