Ammo

[UltimateGuns]

Personally, I use #1 buckshot in my 870 for home defense. Of course, 00 Buck is the old standby.

[Synchronizor]

About shot size for HD...wasn't there a concept of alternating slugs, with 00 buck shot? Is that still considered effective, or is it not used anymore?

I don't know if that was ever widely considered effective. Plenty of armchair commandos seem to like the idea, imagining that they can somehow keep track of the shells in a gunfight, or just figuring that they can blast away in any scenario and at least some of the shells being fired will fit the requirements of the situation. Neither make much sense of you think about it logically & realistically. Buckshot & slugs have different characteristics that serve the needs of different situations, and shotguns have pretty limited magazine capacities, so it's best to just pick one type of ammo that best meets your needs. For HD, that's generally buckshot (though not necessarily 00B) since slugs penetrate way more than necessary for close-range work on humans, and don't have the statistical advantage of multiple wound paths.

For some folks such as those living in rural areas, there is a possibility of having to make longer-range shots in addition to close-range work. A common approach to being prepared for that is to keep the HD scattergun loaded with buckshot for the likelier scenario of a close-range threat, but have slugs handy on or near the gun that can be quickly port-loaded if a long-range shot is required.

I saw a smooth bore barrel on Midway's website; is this ok for firing a slug?

Most slugs are designed to be fired out of smoothbore barrels. Really tight chokes (like turkey chokes) shouldn't be used when shooting slugs, but if you're looking at combat/defensive barrels, you shouldn't have to worry about that. Certain slugs are intended to be used in special rifled shotgun barrels, and will tumble if fired out of a smoothbore barrel, but that just makes them inaccurate, you won't hurt the gun at all.

Also, what is the best choke choice for shooting 00 Buck for HD?

Really, anything from Cylinder to Full will get the job done for shooting someone coming through your bedroom door. The ranges inside a house generally aren't long enough for chokes to matter too much. Cylinder is pretty standard for HD/tactical shotguns aimed at civilians, while IC or Modified are frequently found in law enforcement shotguns that may have to be used at longer ranges. Skeet (between Cylinder & IC) and Light Modified (between IC & Modified) would also be decent choices for a defensive shotgun if you want to fine-tune things a little more, though I don't think I've ever seen a tactical-length fixed-choke barrel with either of those constrictions.

00 Buckshot loads actually vary quite a bit, so if your barrel has interchangeable chokes, the best thing to do would be to try different chokes with your preferred HD ammo and see what works best. If you're buying a fixed-choke barrel, I'd recommend Cylinder or IC. Those are the easiest to find and work well with the majority of buckshot & slug loads.