MO HB545

Prohibits the manufacture, import, possession, purchase, sale, or transfer of assault weapons and large capacity magazines (over 10 rounds) in Missouri, with violations classified as a class C felony.

Defines "assault weapon" to include semi-automatic rifles with detachable magazines and certain features (pistol grip, folding stock, barrel shroud), semi-automatic pistols with detachable magazines and certain features, semi-automatic shotguns with specified features, shotguns with revolving cylinders, and conversion kits that can assemble an assault weapon.

Exempts government officers, armed forces members, peace officers acting within their duties, and manufacturers/dealers selling to the armed forces or Missouri law enforcement agencies.

Allows persons who legally possessed assault weapons or large capacity magazines before the effective date 90 days to remove them from Missouri, render them permanently inoperable, or surrender them to law enforcement for destruction without prosecution.

Excludes from the large capacity magazine definition ammunition feeding devices permanently altered to hold 10 or fewer rounds, .22 caliber tube feeding devices, and tubular magazines in lever-action firearms.