Passengers can check most guns and firearms. They cannot, however, check raw gunpowder or flares in their checked luggage. Ammunition, guns, and flare guns are all allowed in checked luggage.
Travelers cannot, under any conditions, take blasting caps, dynamite, fireworks, hand grenades, plastic explosives or any explosive replicas on planes. Essentially, if it looks like an explosive it cannot be taken onto a plane, even if it's fake.
Most flammable items cannot be taken on planes in checked luggage, including aerosol, fuels, gasoline, gas torches, lighter fluid, strike anywhere matches, flammable paint, turpentine or paint thinner. Lighters and matches are allowed in carry-on luggage but not in checked luggage.
Most volatile chemicals cannot be taken on planes in any form, including chlorine, fire extinguishers, liquid bleach, spillable batteries, spray paint, tear gas or vehicle airbags. Flammable liquids, gels and aerosol paint cannot be taken on planes.
Many airlines require that bags checked on domestic flights weighs less than 50 pounds; if a bag weighs more than this, there is an extra charge. For international flights, the weight limits are often more forgiving. Maximum dimensions vary from airline to airline, so check with your carrier before attempting to fly with a large bag.
