What about sticking with a Mossberg 20 ga pump youth model similar to his .410? I like the Mossberg youth guns. Another option might be a youth semiauto. In the price range you are shopping, you are not going to get a real quality over under, but you can get a very reliable pump or semiauto.

 

Academy carries a youth Yildiz 20 ga O/U. To me is a much better gun than the 555. I've been shootign the full size 20 for over 6 years with zero problems..........Friend has a 555 O/U in 410. After 2 tears of shooting it the forend latch in the barrel lug is worn/loose. Cause the forend to wobble about.

 

I have a Browning Silver Field Micro Midas that he will use eventually. This all started because I bought the wife a Franchi Instinct Catalyst to replace the Browning. I shoot a 686 sporting, so he wants an over under like Dad & Mom. The issue with semi's and pumps is they are very front heavy. I had to add 6oz to his mini Mossberg to balance it out. The Silver Field's stock has no room to add any weight. So really, I'm looking for a 2 to 3 year gun until he can support the forward weight of the Browning. The Yildiz might be a good option.

 

I have seen a few people with the Yildiz. The only complaint I hear is they claim it “kicks harder than other guns”. Just don’t expect to get much if any of the money back you spend on it.

The important thing is your keeping your son interested in the sport by getting him a gun like mom and dad have so good on you.

 

WOW
Hope all dads are like you!
I think Silver Reserve Bantam is a great start, with your guidance of course

 

The thing is, at 8 years old, he's going to outgrow it in a couple years. At 8 I got my kids, now grandkids, the mossberg bantam pump. This gun has stock spacers that can be added or removed. I think I paid $200 used. Oldest grandson just graduated to a Stoeger 3020 adult sized gun. The Mossberg went back in the safe waiting for his little brother.

As to the O/U, I'd wait until he's into an adult sized gun when one considers the cost vs value proposition.