Semiwadcutter

A semiwadcutter or SWC is a type of all-purpose bullet commonly used in revolvers. The SWC combines features of the wadcutter target bullet and traditional round nosed revolver bullets, and is used in both revolver and pistol cartridges for hunting, target shooting, and plinking. Full wadcutters frequently have problems feeding from magazines reliably in automatics, so SWCs may be used when a true WC is desired but cannot be used for this reason.

The basic SWC design consists of a roughly conical nose, truncated with a flat point (called a meplat), sitting on a cylinder (A at right). The base of the cone is slightly smaller in diameter than the cylinder, leaving a sharp shoulder. The flat nose punches a clean hole in the target, rather than tearing it like a round nose bullet would, and the sharp shoulder enlarges the hole neatly, allowing easy and accurate scoring of the target. The SWC design offers better external ballistics than the wadcutter, as its conical nose produces less drag than the flat cylinder. A typical modification is to alter the conical section to make the sides concave, to reduce the bullet mass, or convex, to increase it. B shows a concave sided SWC, typical of a lightweight .45 ACP bullet used in bullseye shooting. The concave sides reduce the bullet weight, and thus the recoil, while keeping the overall length of the bullet long enough to feed reliably in a semi-automatic pistol such as the M1911 commonly found in bullseye competitions.

Some of the most famous SWC designs were developed by Elmer Keith for use in handgun hunting. These designs (C) use a wider front, and convex sides on the "cone" in front. This puts more weight in the front of the bullet, allowing a heavier bullet with no reduction in case capacity. Since Keith was a prime motivating force in the development of the first magnum handgun cartridge, the .357 Magnum, he was very interested in maximizing the amount of case volume for the slower burning powders needed to push heavy bullets at high velocities. The choice of bullet for the .357 Magnum cartridge varied during its development. During the development at Smith & Wesson, the original Keith bullet was modified slightly, to the form of the Sharpe bullet, which itself was based upon the Keith bullet, but which had 5/6 of the bearing surface of the Keith bullet, Keith bullets typically being made oversized and sized down. Winchester, however, upon experimenting further during the cartridge development, modified the Sharpe bullet shape slightly, while keeping the Sharpe contour of the bullet. The final choice of bullet for the .357 Magnum was thus based on the earlier Keith and Sharpe bullets, while additionally having slight differences from both.

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