The L.E. Wilson Neck Sizing Die Bushing 312 is a hardened stainless steel neck bushing built for reloaders who want precision control over case neck tension. These bushings work with L.E. Wilson neck sizing dies to fine-tune how snugly your cases hold bullets—critical for consistent accuracy and reliable feeding, especially in precision rifle and competition loads. Wilson manufactures these bushings in .001" increments, giving you granular control that makes a real difference when you're chasing tight groups or dealing with brass that's been fired multiple times.
The 312 bushing is marked with its nominal size, which represents the middle of the bushing's bore—reamed with a .003" taper to manage case neck spring-back predictably. For most applications, you'll use the bushing in the standard orientation. But here's where Wilson bushings earn their reputation: if your brass has hardened and won't hold bullets securely, or if you need to fine-tune sizing for less squeeze than stepping down to the next smaller bushing, you can flip the 312 over (markings facing the case) to achieve slightly tighter sizing. It's a smart design feature that saves you from buying multiple bushings for subtle adjustments.
Wilson bushings are made to similar specifications as Redding neck bushings but won't fit Forster or RCBS dies—compatibility matters, so verify your die manufacturer before ordering. To select the right bushing size, measure your loaded cartridge's outside neck diameter and subtract .002" to .003" to allow for natural brass spring-back, or calculate based on case neck wall thickness and bullet diameter using the same reduction formula. Whether you're a handloader optimizing for match-grade accuracy or managing used brass with inconsistent neck hardness, the 312 gives you a reliable, durable tool for the job.
Key Features
- Hardened stainless steel construction for durability and consistency
- Manufactured in .001" size increments for precise neck tension control
- Reversible design: use standard orientation for normal sizing, or flip for tighter sizing on hardened brass
- .003" taper bore accounts for natural brass spring-back
- Compatible with L.E. Wilson neck sizing dies (not compatible with Forster or RCBS)
Specifications
| Brand | L.E. Wilson |
| Product Type | Neck Sizing Die Bushing |
| Nominal Size | 312 |
| Material | Hardened stainless steel |
| Size Increment | .001" |
| Bore Taper | .003" |
Frequently Asked Questions
Will the L.E. Wilson 312 bushing work with my Forster or RCBS neck sizing die?
No. L.E. Wilson bushings are not compatible with Forster or RCBS dies. They are designed to work only with L.E. Wilson neck sizing dies. Verify your die manufacturer before purchasing.
How do I choose the correct bushing size for my cartridge?
Measure the outside neck diameter of a loaded cartridge and subtract .002" to .003" to account for brass spring-back—that target is your bushing size. Alternatively, measure your case neck wall thickness, multiply by two, add your bullet diameter, and subtract .002" to .003". These methods ensure proper neck tension without over-squeezing.
Can I flip the bushing over to get different sizing?
Yes. The standard orientation uses the marked size. Flipping the bushing over (markings facing the case) achieves slightly tighter sizing. This is useful for fine-tuning brass that has hardened from multiple firings or when you need less squeeze than stepping down to the next smaller bushing would provide.
What's the difference between the marked size and the actual bore?
The marked size represents the middle of the bushing, where the bore is reamed with a .003" taper. This design allows the bushing to predictably manage how much your case neck springs back after sizing, giving you consistent neck tension shot to shot.
