I've got a Super-14, .223. It will absolutely drive tacks and at an impromptu bet on a range day, it made me look like I knew what the heck I was doing (and I knew how to roll a handload!) at 300 yards. I've had it since 1994 when I bought it new. I don't shoot it nearly as often as either of us deserves.
I have a 10-inch .44 Magnum barrel that I don't use and would like to sell or trade. It's a round barrel, not octagon and it's not a hotshot barrel, not braked or choked or any of that. No fore-end piece for it.
I'm interested in a .30/30 or a 7-30 Waters barrel... no idea why, just something to goof with I suppose. I don't really hunt.
I'd probably have a blast with a .357 Max barrel, too, but then I'd have to hunt down some brass.