Hornady Cartridge Gauge .400" .40 S&W / 10mm
$20.83
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The Hornady Cartridge Gauge in .400" (for .40 S&W and 10mm) is an essential reloading tool for handloaders who demand reliability and consistency. Whether you're loading for carry, competition, or the range, this cartridge gauge lets you verify that your finished rounds will chamber safely in a SAAMI-spec firearm. It's a simple check that catches mistakes before they reach your gun — something any serious reloader should have in the toolbox.
Hornady's Lock-N-Load system is built around speed and repeatability without sacrificing accuracy. The gauge itself is straightforward to use: chamber a finished round and confirm it seats properly. This quick verification catches oversized cases, excessive bullet seating depth, or other dimension problems that might otherwise cause feeding or chambering issues downrange. For handloaders working multiple calibers or experimenting with new loads, individual gauges for each caliber are worth the investment.
This .400" gauge covers both .40 S&W and 10mm in a single tool, making it practical for shooters who reload both cartridges. Keeping one at the loading bench takes seconds to use and eliminates guesswork about whether your ammo will actually fit your chamber.
Key Features
- Checks loaded ammunition against SAAMI chamber specifications
- Covers both .40 S&W and 10mm cartridges
- Part of the Hornady Lock-N-Load system
- Quick bench verification before shooting
Specifications
| Caliber | .40 S&W / 10mm (.400") |
| Brand | Hornady |
| Type | Cartridge Gauge |
Frequently Asked Questions
What does a cartridge gauge actually tell me?
A cartridge gauge confirms that your loaded ammunition will fit into a SAAMI-specification chamber. If a finished round chambers smoothly in the gauge, it should chamber safely in spec firearms. If it doesn't, you've caught a problem before it reaches your gun.
Can I use this gauge for both .40 S&W and 10mm?
Yes. This single gauge is sized for the .400" diameter shared by both .40 S&W and 10mm cartridges, so one tool handles both calibers.
Do I need a separate gauge for each caliber I reload?
If you reload multiple calibers with different diameters, you'll need separate gauges for each. This gauge covers .40 S&W and 10mm only.
Is this a headspace gauge?
No. This cartridge gauge checks overall fit and dimension of a loaded round. Headspace gauges measure case length and primer depth separately and require their own dedicated tools.
