I use a Rossi Youth 410/22LR to shoot 410 in but do have an older model H&R 410 shotgun as well.
The Rossi 410 feels like it weighs about 3 lbs and with the 3" 5--000 buckshot loads will put them all on a paperplate at 30 yards. Throws a good pattern with 4's and 6's High Brass and with the 00 buckshot loads as well. It has a modified choke, so a full choke gun may pattern tighter and be good out to 35 yards with the .36 triple ought buckshot loads. I haven't tried them in the old H&R yet, but I will.
I bought a a giant stack of 410 buckshot/slug loads and and about 10 boxes of high brass Winchester and Remington shells for $1.25 and $4 a box respectively, so I'm stocked up on 410.
That being said, I'd like to get a 410 or 20 ga double with the screw in chokes and might try an over /under.
I have an old Remington 12 gauge double with hammers that I killed my first deer with. Its an 1889 model but has the steel barrels and my Dad used to duck hunt with it until they made fun of him so much he finally got a Rem 1100.
It'll kick bejeesus out of you but throws the best buckshot patterns that I've seen with an old gun. It'll put them all on a paper plate at 40 yards using #1 buckshot 2 3/4" or 00 buckshot. I got the hole kill zone on that deer that I shot with it. It hit it in the head, neck, chest, broke its back, instant summersault to the ground hit from 20 yards