Look at the base models of any of the big makers Beretta, Browning,etc.. They are your best valve in the market. They can also be rebuilt to keep going for a life time for little money. Used ones in good shape are even better buys.
Most quality guns will die from abuse not use.
Look on the EE for trap guns some at a very good price.
Seem like a bit of an odd question though. You are already shooting 6000 rounds in trap? With a Stevens 311?
Are you shooting competitivly? Seems like a very big investment in ammo for shooting with a gun so poorly designed to do this job.
Part of the fun of all this is finding the right toll for the job.
I don't think I'd say competitively, but lots of trap, sporting clays, 5 stand type stuff. So yes I'm shooting about that many rounds a year with a stevens 311.
The problem is I am a fan of SxS's, and I'd like to purchase a SxS that will stand up, but I don't want to spend $1000-$1500 for a gun that isn't built to take the use, I'd rather save up and buy one that will, but I have no idea how to decide what will hold up in the world of sxs's, short of dropping the money on a Model 21.