The L.E. Wilson 300 AAC Blackout case gage is a precision measuring tool built for reloaders who want tight, consistent headspace and reliable brass life. This single-piece gage lets you verify fired cases quickly and accurately, catching sizing mistakes before they turn into pressure problems or shortened case life. Whether you're working up loads on a new batch of brass or maintaining a long-standing supply, this tool sits between your calipers and your die setup as a critical quality checkpoint.
Proper headspace control is where reloading precision begins. The most common—and easily avoidable—error is oversizing brass, which crushes case life and invites inconsistent pressures downrange. The Wilson gage addresses this by measuring overall length (to flag trimming needs) and datum-to-head length (to confirm correct headspace geometry). A few seconds with a caliper and this gage tells you whether your resizing die is set right or if you're working too hard on the brass.
Built from solid steel with knurled grip for one-handed use, the gage is straightforward and durable—no moving parts, no adjustments needed for standard .300 AAC Blackout cases. It's the kind of tool that pays for itself in brass longevity and load consistency on your first serious reloading session.
Key Features
- One-piece solid construction for reliable, repeatable measurements
- Measures overall length to identify cases needing trim
- Checks datum-to-head length to verify correct headspace
- Prevents costly brass oversizing and premature case failure
- Knurled grip for secure handling
- Works with standard dial or digital calipers
Specifications
| Overall Length | 2.494" |
| Large End ID | 0.473" |
| Small End ID | 0.347" |
| Outer Diameter | 0.991" |
| Finish | Silver with center knurling |
| Included | Gage and instruction sheet |
Frequently Asked Questions
How do I use the L.E. Wilson 300 AAC Blackout case gage?
Insert a fired case into the gage and use a dial or digital caliper to measure the gap between the case and the gage body. This measurement tells you the datum-to-head length. Compare your measurements to your load data or manual to confirm your resizing die is set correctly. Also visually check overall length against the gage to identify brass that needs trimming.
What comes in the box?
The package includes the gage itself and an instruction sheet with setup and measurement guidelines.
Can I use this gage to set my resizing die?
Yes. The gage is specifically designed to help you dial in your 7/8"-14 press-type full-length resizing die so you don't oversize your brass. Once your die is properly set, your cases will maintain correct headspace and enjoy longer life.
Is this gage only for .300 AAC Blackout?
This gage is manufactured for .300 AAC Blackout specifications. The internal dimensions are matched to that cartridge; using it for other calibers may not provide accurate results.
