.218 Mashburn Bee

.218 Mashburn Bee

The .218 Mashburn Bee is an “improved” version of the standard .218 Bee cartridge, featuring less case taper, a sharper shoulder, and optimized case geometry to increase velocity and performance while retaining much of the parent case’s characteristics. Handloaders who pursue the Mashburn variant often note gains of about 10-15% in velocity over the standard Bee when using modern powders and well-prepped components.

In practical use, you’ll see bullet weights commonly in the 40-to-55 grain range, with lighter bullets achieving higher speeds and heavier bullets providing better stability and energy retention downrange. Powder selections typically include clean-burning, fast-to-medium burn rate types, such as H-4198 and IMR-4227. Accuracy tends to be quite good in rifles that are accurately chambered, especially single-shot or rigid bolt actions that don’t suffer from loose chambers or sloppy feeding.

Case prep is critical with the Mashburn Bee. Because of its sharper shoulder and more aggressive geometry compared to the standard Bee, case forming, annealing, and careful neck maintenance help ensure longevity of brass and consistency of pressures. Seating depth and primer choice are also more influential in the Mashburn variant; small changes can result in noticeable shifts in group size, pressure signs, or feeding performance.

Many shooters who build Mashburn Bees from existing .218 Bee brass report that fireforming is fairly straightforward when done properly, although some shoulder splitting or neck wear can occur if the cases are repeatedly fireformed without annealing. When combined with quality bullets, solid barrels, and well-tuned loads, the Mashburn Bee is capable of tight, impressive groups with velocity that rivals many full-power .22 wildcats.

Source: Handloader Issue #219 – October, 2002