The Hornady Cartridge Gauge in .308 inch for .300 Winchester Magnum (Hornady part no. 380718) lets long-range and hunting reloaders check cases and finished ammunition against SAAMI chamber specifications before a round leaves the bench. Part of Hornady’s Lock-N-Load line of cartridge gauges, it catches an oversized case or a bullet seated too long before it turns into a hard chambering or a missed shot in the field. Reloaders building precision .300 Win Mag loads use this gauge as a final consistency check across a batch.

Key Specifications

• Gauges cases and ammunition to .300 Winchester Magnum chamber dimensions.
• Checks fit against SAAMI chamber specifications.
• Part of Hornady’s Lock-N-Load cartridge gauge lineup.
• Ships at approximately 0.34 lb.
• A round that seats flush in the gauge falls within SAAMI chamber tolerances; one that does not should be set aside before firing.

Frequently Asked Questions

What cartridge is this gauge built for? .300 Winchester Magnum.

Why check magnum hunting loads before a hunt? A round that fails to chamber cleanly in the field can cost a shot opportunity; the gauge catches that risk beforehand.

Buy the Hornady Cartridge Gauge .308in, .300 Win Mag

Confirm every .300 Win Mag round chambers cleanly before your next hunt. Order from Hornady through our reloading equipment lineup, with fast shipping from our Lubbock, Texas gun shop.