Hornady Lock-N-Load Cartridge Gauge 300 Blackout

• Go/no-go chamber gauge for 300 AAC Blackout handloads
• Checks sized cases and loaded rounds against SAAMI min/max chamber dimensions
• Identifies over-sized or out-of-spec rounds before they reach the rifle
• Calibre-specific design — built for 300 Blackout only
• Particularly useful when working with formed brass (e.g. trimmed .223 cases)
• Part of the Hornady Lock-N-Load precision reloading tool range

The Hornady Lock-N-Load Cartridge Gauge for 300 AAC Blackout is a calibre-specific reloading tool that allows handloaders to confirm their sized cases and loaded rounds sit within SAAMI chamber dimensions for this cartridge. The 300 Blackout is particularly popular with those using suppressed rifles, where reliable feeding and chambering are critical — and the cartridge's shorter overall length and .308-calibre bore mean cases formed from trimmed .223 brass can vary more than factory-produced brass if not checked carefully. A round that is even fractionally over-sized may cause a malfunction when you can least afford one. This gauge provides a quick go/no-go check: rounds within SAAMI tolerances pass freely, while over-sized rounds are flagged before they reach the rifle. No additional tools are needed and the check takes only seconds per round. Part of the Hornady Lock-N-Load precision measuring range, designed to support accurate and consistent handloading.

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