I bought a Rossi .410 single shot in 2015. I used it 2 times and it does a fine job on squirrels and is light enough for use as a little backup shotty. Without a rib it is hard to aim or point as I am not really sure where the bead should be. I guess I should ignore the space between the bead and the bump on the receiver and just use the bead to point. I know you point a shotgun but I have had 3 of these single shot type 410s and they are all a PITA to shoot until ya get used to them.
I love it. I had a Rossi 410 as a camper gun. As you say, very light. I used a triangle file to put a small notch in the top of the receiver as a sight reference. It shot slugs like a rifle out to 25 yard's. If I find another one at a good price, I'm going to buy it.
I sold mine to a couple at church. His wife wanted a gun for his birthday to have in their camper and around the house. The last that I heard, he had killed 11 skunks using slugs
I also have a Mossy 410 Bantom Youth Model 500. I have the original vent rib barrel plus an 18" riot barrel. Great for HD and hunting. It also shoots slugs like a rifle. I have several hundred rounds including shot shells, #4 buck, 000 buck, 1/4 oz & 1/5 oz slugs.
I used to love hunting Quails witha 410 and then fell away from them. After they came out with the 000 buck loads, it resparked my interest and gave me a new reason to own one.