Lyman Flash Hole Uniforming Tool

The Lyman Flash Hole Uniforming Tool removes burrs from inside the flash hole in cartridge cases. During case manufacture, punching the flash hole can leave raised brass around the opening. The tool removes these burrs so the internal flash-hole opening has a clean, consistent edge. Lyman specifies the tool for rifle and pistol cases from .22 through .45 calibre.

The tool uses an adjustable cone-shaped case adapter to set the cutting depth for different case lengths. In addition, the cutter enters through the case mouth and works from inside the case. Consequently, reloaders can prepare the internal flash-hole area without altering the primer pocket.

Lyman identifies this model as part number 7777760. The supplied assembly includes the cutter shaft, adjustable case adapter and handle.

Lyman Flash Hole Uniforming Tool Features

First, the tool removes the burr that can remain around the internal flash-hole opening after case manufacture. As a result, the flash-hole opening has a cleaner internal edge between the primer pocket and the inside of the case.

In addition, the adjustable cone adapter lets you set the cutter for different case lengths. The adapter slides along the shaft and locks into position with a set screw. Therefore, you can adjust the tool to suit the cases you are preparing.

Furthermore, the cutter uses a clockwise turning action to remove the burr. Lyman specifies a clockwise turn for the cutting operation. However, the amount of turning required can vary according to the case and the adjustment of the tool.

The tool covers cases from .22 to .45 calibre, making it suitable for a broad range of common rifle and pistol cartridges. Moreover, the adjustable adapter allows the same tool to accommodate different case lengths within that range.

For additional case-preparation equipment, see our Case Preparation. You can also view our Reloading Equipment. For further product information, visit the Lyman manufacturer website.

Application and Specifications

Before using the tool, make sure the case has no primer installed. Next, insert the uniformer shaft through the case mouth and align the cutter with the flash hole. Then adjust the cone adapter to establish the cutting depth and lock the adapter in position.

After that, turn the tool clockwise until you feel the cutter stop. Use a modest cutting depth and remove only enough brass to eliminate the burr. Therefore, avoid excessive cutting that could remove unnecessary brass from the case.

Once the operation is complete, inspect the flash hole and remove any loose brass. The tool focuses specifically on internal flash-hole burr removal, so it provides a dedicated preparation step alongside other case-preparation operations.

Because the cutter enters through the case neck, you can access the internal flash-hole opening without working through the primer pocket. In addition, the adjustable adapter allows the tool to accommodate different case lengths.

What’s Included

• Flash hole uniformer cutter shaft assembly
• Adjustable cone-shaped case adapter
• Lyman multi-purpose wooden handle
• Handle assembly components

Overall, the Lyman Flash Hole Uniforming Tool provides a dedicated method for removing internal flash-hole burrs. Its adjustable adapter accommodates different case lengths, while the .22–.45 calibre range covers a wide selection of rifle and pistol cases. Consequently, it fits naturally into a broader case-preparation process.