The L.E. Wilson 270 WSM case gage is a precision reloading tool that lets you measure fired brass accurately and set up your full-length resizing dies with confidence. Whether you're a methodical handloader who trusts data over guesswork or you're tired of guessing whether your brass is sized correctly, this one-piece gage checks two critical dimensions: overall length (to flag cases needing trim) and datum-to-head length (to nail your headspace). Getting headspace right is non-negotiable—oversize your brass even slightly, and you'll burn through cases fast and risk inconsistent pressures. This tool helps you avoid that mistake.
The gage works with your dial or digital caliper to give you repeatable, objective measurements. Set your 7/8"-14 full-length resizing die using the datum-to-head reading, then verify your finished brass is sized correctly. Check overall length separately to catch cases that have grown and need trimming before they go back in the press. It's the kind of low-tech, high-reliability method that serious 270 WSM reloaders have relied on for decades—no batteries, no guesswork, just metal-to-brass contact and your calipers.
The gage comes as a single unit with instructions, packaged in a cardboard box. The design is straightforward: a stepped cylinder with a large diameter at one end (checks the shoulder area) and a smaller diameter at the other (indexes off the case head). The knurled grip in the middle keeps your hands steady during measurement. If you're loading 270 WSM in volume, this gage will pay for itself in brass you don't waste and the peace of mind that comes from knowing your headspace is dialed in.
Key Features
- Measures overall length to identify cases requiring trimming
- Checks datum-to-head length for accurate headspace verification
- Helps prevent oversizing and premature brass failure
- Works with any standard dial or digital caliper
- One-piece design for durability and simplicity
- Knurled grip for secure handling during measurement
Specifications
| Brand | L.E. Wilson |
| Caliber | 270 WSM |
| Type | Case Gage (one-piece design) |
| Overall Length | 2.494" |
| Large End Diameter (ID) | .473" |
| Small End Diameter (ID) | .347" |
| Outer Diameter (OD) | .991" |
| Finish | Silver with knurled middle section |
| Included | Gage and instructions |
Frequently Asked Questions
What calibers does this case gage work with?
This gage is designed specifically for 270 WSM (Winchester Short Magnum) cartridges.
Do I need calipers to use this gage?
Yes. You'll use a dial or digital caliper to measure the distance between the gage and your fired case at two points: overall length and datum-to-head length. The gage provides the reference surfaces; the caliper provides the measurement.
How does this help prevent oversizing my brass?
By measuring your datum-to-head length after resizing, you can verify that your die is set correctly. Oversize brass has too much material and will measure longer in the datum area. Catching this early keeps your cases lasting longer and your pressures consistent.
Will this work with my 7/8"-14 reloading press?
This gage is specifically designed to help you set up 7/8"-14 full-length resizing dies, which are standard on most popular reloading presses. The measurements you get from the gage guide your die adjustment.
