Right now....For an SD shotgun, I have 300 shells of 00 buckshot and 150 of #1 buck --- also 200 rifled slugs (Federal LE Tactical TruBall)
Also consider if you have close neighbors or live in an apartment, full power 00 buck might not be a wise idea.
As for the slugs, I'm just as accurate at 50-60 yards with the Federal loading as I am with an AR15 in 5.56 --- if I know my range will not exceed that, I'm grabbing the 12-gauge with rifled slugs every time.
I have found that #4 buck is real handy ammo to have, it will dispatch a raccoon or woodchuck very nicely and of coarse some #7 1/2 or #8 for game birds. Ya never know, that shotgun will be mighty handy if the SHTF as your primary weapon with all that virsitality....
My reserves aren't too high at the moment, but i try to keep a number of options in stock. I've got about 75 rounds of #8 shot, 35 rounds of 00 Buckshot, and about 25 rifled slugs. I keep the Mossberg loaded with the #8 shot because the spread won't be too far at HD distances, and less chance of shooting through a wall and into the neighbors house or the street.
I have a around 200 rounds of mixed buck and 100 of slugs. Along with about a case of Bird shot. MY 12 g is my go to gun if its going to be a battle it does a lot of damage. If I need to go out further then I grab the 30.06. I also have several handguns around. But I love my Mossy 500 Its just built like a tank. I use a Limbsaver shoulder pad the I replaced the original with what a difference, When they say 50% reduction I have to believe it. I have had shoulder surgery and shooting that thing was punishment now its like a 20 gauge.
Like NYPD and .45 Forever, I prefer 00 and Rifled Slugs. I keep a ratio of about 4-1 Buckshot over slugs.
Currently, I maintain about 300+ 00 Buckshot, 100 Assorted buckshot, more # 4 buck than the remaining 000, 0, 1 and 4 buck.
I also have a box of BBB, BB, # 2 birdshot, T, and 4 size birdshot, as well as 500+ rounds of 7 1/2. I feel the #4 buck with 27 pellets would be a good street sweeper at 50 yards, not necessarily a letal round at 50 yards, but would sure keep folks from wanting to advance. the remainder of #2 birdshot and larger up to BBB .18 caliber, would be great for killing *****.
For home defense, I would probably never recommend anything smaller than #2 birdshot no matter how close you are. Bigger shot = deeper penetration.
I bought a lot of the heavier birdshot just because I got a deal on it. I have a lot of 7 1/2 shot for dove and quail and clay pigeons.
I also have a lot of 3" magnum loads, that I would gladly trade for standard or low recoil rounds, that I have bought on Clearance. I have some #5 turkey loads with 1 7/8 ounce loads that I wouldn't be ashamed of using for home defense, I just don't like being punished that much being on the shooting end.
I do have a couple of boxes of low recoil 00 which will be relegated to my pumps. If 8 pellets of 00 isn't getting the job done, you are most likely in deep dodo anyhow and need a .50 Barret instead. At close range, I suspect a slug may be as devastating as a .50.
Slugs can reach out, Like NYPD said, and they are great for penetrating autos.