Die Shims For Full-Length Sizing Dies — EZ Die Adjusting
When your cases become hard to extract, or you feel a stiff bolt lift when removing a cartridge, it’s probably time to full-length size your cases, and “bump” the shoulder back. Short-range benchrest shooters, running high pressures, typically full-length size every load cycle, bumping the shoulder .001-.002″. The vast majority of mid-range and long-range F-Class shooters also full-length size every time. High Power shooters with gas guns should definitely full-length size every time, and may need to bump the shoulders .003″ or more to ensure reliable feeding and extraction.
Use Shims for Precise Control of Shoulder Bump
Some shooters like to set the “default” position for their full-length die to have an “ample” .003″ or .004″ shoulder bump. When they need less bump, a simple way to reduce the amount of shoulder movement is to use precision shims in .001″ (one-thousandth) increments. Sinclair Int’l offers a set of seven (7) shims for your standard 7/8-14 FL sizing dies for $14.99.
Sinclair explains: “Each shim is notched for easy size identification. Just set your die using one of the middle thickness shims. Adjustments can be made easily by changing shims to increase or decrease die depth without changing the stem setting. This is a