Does the 1100 have less recoil then the 870? Also, 20 gauge would be more appropriate for a 12 year old than a 12 or 16 gauge?
I used to hunt with a guy who's wife complained how her 20 gauge kicked. He tried it, and it kicked more than his 12. It turned out it was one of the light 20's, so less mass to absorb recoil. Something to consider.
In an auto, the 1100 is good.
---Does the 1100 have less recoil then the 870? Also, 20 gauge would be more appropriate for a 12 year old than a 12 or 16 gauge?---
The 1100 has less recoil than the 870 and is more suitable for clay targets. A lot of people get 20 gauge shotguns for young shooters, but you can get light loads for the 12 gauge that are comparable. I've got a 28 gauge Remington 1100 that's like shooting a BB gun, but the cost of shells is very high. I just like 28 gauge. :^)
12 gauge auto is the way to go.