The RCBS Precision Mic Headspace Gauge, .243 Winchester (brand part no. 88305) lets a .243 Winchester handloader check chamber headspace and bullet seating depth without a separate headspace comparator kit. A few twists of the Precision Mic measure from the datum point on the case shoulder to the case base, reading out spot-on SAAMI tolerances to within 0.001 inch. Reloaders use that reading to set full-length sizing dies precisely and to dial in seating depth for a specific rifle’s chamber and throat. Because it is chambering-specific, it only works for .243 Winchester brass, but for that one cartridge it is a fast, repeatable way to keep loads safe and brass life longer.

Key Specifications

• Measures headspace to 0.001 inch reads from the case shoulder datum point to the base for a precise SAAMI-tolerance check.
• Checks bullet seating depth lets the handloader dial in seating depth for a specific rifle’s chamber and throat.
• Chambering-specific to .243 Winchester machined to this cartridge’s shoulder geometry, so it is not interchangeable with other calibers.
• Extends brass life dialing in precise headspace and seating depth reduces case stretching over repeated firings.

Frequently Asked Questions

What does this tool measure? It measures chamber headspace and bullet seating depth to within 0.001 inch by reading from the case shoulder datum point to the case base.

Does this gauge work for other calibers? No, it is machined specifically for .243 Winchester and is not interchangeable with other cartridges.

Buy the RCBS Precision Mic Headspace Gauge, .243 Winchester

Order the RCBS Precision Mic Headspace Gauge, .243 Winchester from RCBS to dial in headspace and seating depth on your .243 Winchester loads. Pick it up from our Lubbock, Texas gun shop. Browse our reloading equipment lineup for more.