Remington 870, for a reliable economical semi auto I got a Remington SPR 453 (Baikal MP-153) a few years ago for 399. It is 3.5" and the recoil with 3" shells is about non existant. It is threaded for Tru Chokes though, so you don't have the choke options of Rem, Mossberg or pretty well anythin else. Kick's and Carlson's make chokes. I use a Carlson's .665" (it might be .660) which works well. Benelli Novas are a dime a dozen used also, but I like the 870 better.
You could also use "Camo Form" wrap on your current gun which won't mar the finish and comes off easily. It's very similar to 3M Vet wrap if you are familiar with that product.
