1/4" Hex Drive Adapter for the K&M Tapered Reamer
The K&M Case Neck Chamfer Tool (tapered reamer) is one of the finest case mouth chamfering tools available. The tool cuts a shallow 4-degree-per-side chamfer on the inside of the case neck for smooth bullet seating. By default, the tool is operated by hand using the hex knob. This works fine for small quantities, but larger batches will leave your fingers sore.
This 1/4" hex drive adapter solves that problem. One end features a 1/4" hex shank that fits into the chuck of a cordless screwdriver or case prep center, while the other end has a 5/16-18 thread onto which you mount the tapered reamer cutter. This lets you chamfer hundreds of cases without hand fatigue.
Compatibility
The adapter fits all K&M Case Neck Chamfer Tools (tapered reamers) that use a 5/16-18 thread. This covers the entire K&M chamfer tool line from .17 through .50 caliber. Simply unscrew the handle from your tapered reamer, thread the cutter onto this adapter, and clamp the hex shank into your cordless screwdriver.
Use a cordless screwdriver with adjustable speed set to low RPM. Excessive speed can overheat the cutter or produce an uneven chamfer. The K&M Power Adapter Handle is an alternative if you prefer a manual speed handle drive.
Specifications
• Brand: K&M Precision
• Product: hex drive adapter
• Input: 1/4" hex (fits standard drill chucks)
• Output: 5/16-18 thread
• Material: steel
• Compatible with: K&M tapered reamers with 5/16-18 thread
• Origin: USA
Practical tips
If you regularly chamfer batches of 50 cases or more, this adapter is a significant time saver. Pairing the K&M tapered reamer with a slow-speed cordless screwdriver produces the same quality chamfer as hand operation, just much faster. Make sure the cutter is firmly threaded onto the adapter before starting, and check the depth stop fingers on the reamer after mounting.
Combine this adapter with the K&M Case Neck Chamfer Tool for a complete, powered chamfering system. Ideal for precision shooting and competition where uniform case mouth chamfer is essential for consistent bullet seating.
