Brenneke slugs Shotgun slug

a 12 gauge brenneke slug

the brenneke slug developed german gun , ammunition designer wilhelm brenneke (1865–1951) in 1898. original brenneke slug solid lead slug ribs cast onto outside, rifled foster slug. there plastic, felt or cellulose fiber wad attached base remains attached after firing. wad serves both gas seal , form of drag stabilization. ribs impart small amount of rotation projectile travels down bore. rotation not impart gyroscopic stabilization, rather improves accuracy correcting manufacturing irregularities. additionally, ribs decrease contact surface bore, reducing friction , increasing velocity. ribs deform through choke more readily solid slug would, reducing pressure , wear on choke safe levels.

since brenneke slug solid, rather hollow foster slug, brenneke deform less on impact , provide deeper penetration (see terminal ballistics). sharp shoulder , flat front of brenneke (similar in dimensions wadcutter bullet) mean external ballistics restrict short-range use, accuracy similar of american foster slug while retaining improved penetration , slug integrity of brenneke design.