Lyman .300 Winchester Short Magnum Case Headspace Gauge

The Lyman .300 Winchester Short Magnum Case Headspace Gauge is a precision reloading measurement tool designed for reloaders setting correct shoulder setback when resizing .300 WSM brass. This caliber-specific gauge allows reloaders to measure headspace from the case datum line using calipers, helping ensure proper die adjustment, consistent chambering, and extended brass life when producing .300 Winchester Short Magnum hunting or precision rifle ammunition.

Quick Highlights:

• Product Type: Case Headspace Measurement Gauge
• Caliber: .300 Winchester Short Magnum (.300 WSM)
• Measurement Method: Datum Line Headspace Measurement
• Construction: Precision Machined Hardened Steel
• Tool Compatibility: Dial or Digital Calipers
• Application: Rifle case headspace measurement and die setup

Use Cases & Applications:

• Measuring shoulder position on .300 WSM fired and resized brass
• Setting proper shoulder setback during full-length sizing
• Reloading ammunition for .300 Winchester Short Magnum bolt-action rifles
• Precision load development for long-range and hunting rifles
• Maintaining consistent case dimensions across multiple reload cycles

Design & Functional Advantages:

• Caliber-specific gauge measures headspace from the case datum line for precise sizing adjustments
• Enables accurate comparison between fired brass and resized cases
• Helps prevent excessive shoulder setback that can shorten brass life
• Supports smooth chambering and reliable bolt operation in short magnum rifles
• Hardened steel construction provides long-term durability and measurement consistency

Technical Details:

Manufacturer: Lyman
Product Type: Case Headspace Measurement Gauge
Caliber: .300 Winchester Short Magnum (.300 WSM)
Measurement Method: Datum Line Headspace Measurement
Construction: Hardened Steel
Tool Requirement: Dial or Digital Calipers (Not Included)
Application: Reloading die setup and case headspace measurement