Recent figures from the Ukraine War show 80% of casualties are caused by drones. With the advent of fiber optic guidance, the only defenses seem to be protective netting or shooting them down. 
has used drones with mounted rifles to shoot civilians in Gaza. This technology will only become more widespread.
Already, I've seen many drones at protests and demonstrations. We know and have seen there are people who want to shoot or run over demonstrators. It's only a matter of time that drones become weaponized and used against civilians here. I sometimes see people open carry larger guns to defend people at these demonstrations, now an unfortunate necessity. In the future, I propose a shotgun may become more useful.
For shooting clays, many places in the US offer rentals and lessons. Used shotguns are relatively inexpensive. The Mossberg Maverick 88 is a well-regarded, reliable entry-level choice to pickup. I like the 2-barrel combo option for less than $250.
A ribbed barrel with interchangeable chokes is really nice to have for shooting clays. The "security" or "LE" barrels on shotguns typically are a fixed cylinder, suited for slugs and defensive buckshot like Federal Flite Control. One can use those for birdshot, at the tradeoff of more spread and less effective range.
There are all kinds of specialty ammo for shotguns. For Ukraine, they are testing net-launching shotgun ammo.
Now all that said, the recoil of a 12-gauge isn't for everyone. Also common, 20-gauge is a bit smaller and lighter recoiling, and still plenty effective for many purposes. There's also .410, even smaller. That's why I recommend getting a lesson or trying a buddy's.
I have some more thoughts tips and insights that I might share later, and I'm still learning a lot about this discipline. Share your thoughts, tips and insights, and thanks for reading!
You can get fixed barrels with full-choke (no interchangeable choke tubes). These are not supposedly suitable for slugs, fine for buckshot though. NGL though. I have run slugs through a full-choke barrel because I forgot to swap out the choke tube, and it didn't fucking explode or anything (3 1/2" high-brass 12 ga. slugs). Even slugs still run in sabots, so the plastic sabot will compress in the choke. Still wouldn't recommend it. It's probably detrimental for accuracy with slugs.
I only bring this up because bird guns, are long as shit and kind of a pain to lug around. I've got two pumps for birding and clays and they both have 24" barrels, on top of all the extra length of the gun. They are loooooooong bois. One of my other shotties is a semi-auto with an 18-inch fixed full-choke barrel, which isn't great for aerial targets, but is still has a pretty reliable hit rate and isn't nearly as unwieldy.
I'm not rocking $1,500 shit either. I've got one Benelli, and I've never payed more than $300 for a shotgun. Most expensive shotgun I own is a vintage 1970's era 870 Wingmaster I bought second-hand from a guy that did a lot of business with a company I used to work at.
Agree. 12 ga. is not for everyone. You get used to it, but even still... I only run 12 ga. and after a case of 250 shells I still go home with a horrible bruise on my shoulder and a headache. 20 ga. is a little more gentle, and still fully useful for what we'll call "birding" in this discussion. .410 does not have the range, power, or mass though. .410 is snake shot. It's close range, small target. There are handguns that load .410. In a "birding" engagement though, I would still recommend 12 ga, especially with a short barrel. You want the extra velocity and the extra pellet mass. You aren't running a whole case of ammo. Just get used to dealing with a 12, then you can run 20 no problem.
And now...
For shooting at aerial targets. Number one piece of advice I can give you all (other than practice, a LOT) is follow through. When you bring your gun up and track a target, do not stop when you fire. keep tracking the target all the way through. You still need to estimate lead, but human brains are kind of built for that. Track the target, establish the lead you think you need (this is what you need to practice), continue tracking, fire, and then continue tracking. When I was just starting out I would stop tracking as soon as I fired, and would miss most shots. You have to establish that target lead and maintain it all the way through firing. A fully lateral target moves a long way in the hundred or so milliseconds it takes the gun to lock and fire and the projectile to leave the barrel. If you stop tracking, you will shoot behind it.
Also: Please do not shoot rifles or handguns at "birds." You will miss, and bullets are incredibly dangerous landing. Shotguns shoot spheres that have dogshit aerodynamics. They slow down a lot moving through the air, especially bird shot with its low per-pellet mass. Bullets do not slow down significantly enough. Birdshot goes from lethal the mildly annoying after about 200 yards. Bullets stay pretty much lethal until they hit something.
Stay safe out there, and don't shoot your eye out.
I get headaches too, and that's after like 75 rounds. Semi-autos are nicer for recoil, as well as a limbsaver buttpad, and I gaffer tape on a foam cheek-riser/comb to get a proper fit and some extra cushioning.
I find that traditional wood-stock twin-barrel guns are heavier and fatiguing and the recoil is still a cheek bruiser, and yes it was properly fitted and i wasn't leaving gaps in my cheek or shoulder. Last time I went out with a semi-auto, with the mods previously mentioned, as well as a red dot. I ended up doing about the same or a bit better as a traditional rib and bead setup and it was quite comfy. 24" barrel, modified choke. 16/25 at the five-stand setup, only one guy got a better score with 18. He actually said an improved cylinder choke (a bit more open) worked best.
I'm still a noob and I appreciate your input.