Why do you qualify the "sporter" as having open sights vs the "bull" barrel as being scoped? User perception or catalog representation?
The only real advantage of a "bull" barrel 22 is that it may provide a steadier hold. In centerfire calibers, the heavy barrel is a heat sink and does reduce barrel vibration. A 22 doesn't generate enough heat to need the heat sink nor does it burn enough powder to cause as much vibration.
At this time, the second most accurate 22 I have is a Ruger 77/22 with a thin barrel, no sights, and a synthetic stock. It is only marginally less accurate than #1 which is a pre-WW2 Mauser with a barrel twice a large in outside diameter.