Chadwick & Trefethen ''D'' Adjustable Reamer

The Chadwick & Trefethen "D" Adjustable Reamer is a specialized gunsmithing tool designed for competitive shooters and gunsmiths working with 10 and 12 gauge shotgun barrels. If you're dealing with tightly choked 12 gauge barrels that need opening up before final finishing, this reamer is built to handle that intermediate step with precision. The adjustable design gives you control over cut depth, making it an essential tool for custom shotgun work and barrel modifications where standard reamers alone won't get you to your target dimensions.

The blade angle on this reamer is engineered to eliminate chatter during the cutting process—a common frustration when opening up shotgun bores. That means each pass produces a clean, controlled cut without the vibration and surface finish issues that come from tool chatter. Whether you're opening a constricted muzzle or preparing a barrel for final honing, that clean cutting action saves time and reduces the risk of tool marks that would require additional finishing work.

This tool fits into the workflow between rougher operations and final polishing. If you're working with a 12 gauge barrel that's particularly tight, the "D" reamer often serves as the bridge before moving to the "E" reamer for final sizing. That staged approach helps you achieve precision without overloading a single tool or risking runaway cuts in stubborn steel.

Specifications

Frequently Asked Questions

What gauge shotguns does the "D" reamer work on?

This reamer is designed for 10 and 12 gauge barrels.

When would I use the "D" reamer versus other Chadwick & Trefethen reamers?

The "D" reamer is particularly useful as an intermediate step for tightly choked 12 gauge barrels before using the "E" reamer for final sizing. It helps open stubborn chokes in a controlled manner.

Does the adjustable design let me control the cut?

Yes—the adjustable blade angle is designed to eliminate chatter and produce clean, controlled cuts with each pass, reducing vibration and surface finish problems during the reaming process.