Long action magnum builds demand tighter tolerances than factory cartridges require. Standard reamers cut for mass-produced brass don’t account for Sherman’s efficient case geometry or 40-degree shoulders. You’re left with a chamber that either doesn’t fully support the brass or leaves performance on the table.
Sherman long action reamers are custom-made by JGS or Manson for Sherman Magnum and Mega cartridges. Available in high-speed steel or carbide with oil groove bushings for clean, fast cuts that maintain dimensional accuracy. Carbide reamers not listed are available on special order for specific builds.
These reamers are part of a matched system built around head-stamped Sherman brass. Our focus is keeping head-stamped cartridge reamers in stock, though availability can vary. Backorders run approximately 12 weeks. Call or email for current inventory before ordering if timing matters.
The result is a long action chamber that handles heavy, high-BC bullets at max velocity without the compromise of adapting generic tooling to a wildcat build.