For your shotgun to live up to its reputation for versatility and do a proper job for you, it is critical that you load it with the correct ammunition for the given task.. Birdshot is, as its name implies, best suited for shooting feathered food, though it is also appropriate for small game such as rabbits and squirrel within range, and for shooting produce-stealing varmints such as woodchucks at across-the-garden distance.
With smaller pellets, such as the tiny #8 or #9, birdshot will take small birds like doves without destroying the meat. Larger lead pellets will bag wild turkey, and large steel or bismuth pellets are the ticket for ducks and geese. (Lead birdshot pellets are forbidden for hunting migratory waterfowl, since spent shot collects at the bottom of bodies of water where the birds may swallow it, causing lead poisoning.)
Moving up from birdshot, the next progressive step on the shotgun ammo ladder is buckshot. The implication of its name to the contrary, this is not the best ammunition to use for deer unless local law in densely populated areas demands it. The most popular load, 00 buckshot (“double-ought”) comprises nine .33 caliber plain lead or copper jacketed pellets when loaded in a 12 gauge shell. I have seen deer that were strafed from stem to stern with 00 buckshot from full choke (longer range) shotguns, with the pellets merely stuck in their hide where they lodged without penetrating into the animals’ body cavities. Buckshot is a very close range proposition. It is actually at its best as an antipersonnel load, favored by the military for jungle warfare and embassy guard duties (it proved horrendously effective in the trenches during WWI), and by police. This writer uses buckshot as a home defense shotgun load, with #1 Express (full power) buckshot in the semiautomatic 12 guage. This delivers 16 .30 caliber pellets that strike with optimum penetration for erect bipeds, and with optimum pattern saturation at distances from close range to 15 yards. These pellets will normally stay inside the assailant’s body with a front to back shot, reducing danger to innocent bystanders who might be located unseen behind a violent criminal. ~ Massad Ayoob