The L.E. Wilson Neck Sizing Die Bushing 337 is a hardened stainless steel bushing designed for reloaders who want precise, consistent neck tension on their fired brass. If you're working with a progressive or single-stage reloading press and need to fine-tune how snugly your cases grip the bullet, this bushing gives you control that standard full-length sizing dies can't match. Wilson bushings are made in .001" increments, so you can dial in exactly the sizing pressure your loads demand—whether you're loading match ammunition at the range or precision hunting rounds in the field.
The marked size refers to the middle of the bushing, which is reamed with a .003" taper. This matters: since the case neck only contacts the bushing's middle section, you have a clever option for fine-tuning. Flip the bushing over so the marking faces the case (markings down) for a slightly tighter size—useful if brass has hardened and lost tension, or if you want to dial in less "squeeze" than the next smaller bushing would give you. It's a practical solution when standard step-up isn't quite right.
L.E. Wilson bushings are manufactured to specs similar to Redding neck bushings, but they are not interchangeable with Forster or RCBS dies, so verify your press compatibility before ordering. Whether you're chasing sub-minute-of-angle groups or just want repeatable, uniform neck fit, this bushing puts the control in your hands.

