The Hornady Lock-N-Load Cartridge Case Length Gage (Model 380714) is a standalone, single-cavity mechanical inspection tool designed to verify that resized brass and completed ammunition conform to minimum SAAMI chamber dimensions. Precision-machined from high-carbon steel, this handheld cylindrical drop gauge provides rapid Go/No-Go confirmation of shoulder headspace datum positioning and overall case length to prevent feeding malfunctions and chambering failures in bolt-action and pump-action rifles.

Key Features

• SAAMI-Tolerance Chamber Verification: Machined to strict minimum SAAMI chamber dimensions to ensure handloaded or factory cartridges chamber smoothly and safely.
• Dual-End Inspection Steps: Features integrated reference steps on both the mouth and head ends to immediately identify incorrect shoulder headspace and overall case length.
• Non-Powered Mechanical Operation: Functions as a purely mechanical Go/No-Go drop tool requiring 0V power and no batteries.
• Durable High-Carbon Steel: Built from precision-machined, unplated high-carbon steel engineered for repeatable pass/fail dimensional testing.

Specifications

• Model Number: 380714
• Calibre Compatibility: .300 AAC Blackout (.308" bullet diameter)
• Material: High-carbon steel
• Capacity: Single-cartridge drop capacity (1 round at a time)
• Power Requirements: 0V (purely mechanical)
• Measurement Standard: SAAMI minimum chamber tolerances

Who is the Hornady Lock-N-Load Cartridge Case Length Gage for?

• Handloaders forming .300 AAC Blackout brass from parent cases — Verifies correct shoulder datum location and overall trim length when converting .223 Rem/5.56 NATO parent brass using this single-cartridge headspace gauge with a dedicated single-cavity capacity for .308" bullet diameter specifications.
• Reloaders and shooters quality-checking completed ammunition — Provides instant pass/fail chamber clearance inspection across single-cartridge drops to prevent chambering jams and feeding failures in standard .300 AAC Blackout firearms.

Less suitable for: Relaying exact numerical headspace setback measurements down to thousandths of an inch (use a dial caliper with an attached headspace comparator set) or checking other chamberings such as .223 Rem, 6.5 Creedmoor, or .308 Win (use a dedicated calibre-specific cartridge gauge).