Can't say for the heavy bbl. I've got the std.
One-hole 10-shot groups at 10 yds. Teensy ones with ammo it likes.
I like the way it handles better than a (stock) 10/22. Bigger stock, feels more like it was designed for an adult. I would think a heavier bbl would improve the feel (it's a little "whippy" up front with the std bbl).
I have run many thousands of rounds through my 597. I don't clean it. It works flawlessly with ammo it likes (may choke one or two percent of the ammo it doesn't like - which, of course is the one I have hundreds of rounds of lying around). Trigger is just fine for the money.
Don't know about the heavy bbl, but the std 597 is a pretty nice deal (you can find them at K-mart for under $130 on sale; lowest I've ever seen was $124).
