For home defense options, what's more effective? Buckshot or birdshot? Roy Huntington, editor of American Handgunner, takes on this question after field testing 00 buck and #8 birdshot out of a Remington 870 at a close-range target.
The buckshot versus birdshot debate is practically as old as the first home-defense shotgun, and yet the argument has never really evolved. The pro-buckshot gentleman argues nothing penetrates like 00 buck, while the birdshot proponent argues birdshot minimizes collateral damage because it won't bust through drywall (though some tests indicate that birdshot will indeed penetrate drywall at close-range). Often, the discussion never waivers from these points. However, while penetration is probably the key difference between birdshot and buckshot, there is another important consideration that too often goes unheeded.
Rifled barrels, as I touched on above, are basically intended to shoot certain types of slugs. If buckshot or birdshot are used in rifled barrels, exceptionally poor patterns and accuracy will be noted, even at very close range. However, with slugs, rifled barrels are extremely useful and accurate. For other purposes, go with a smoothbore shotgun barrel.