PGA Tour veteran Doug Barron shot 66 and is one shot back. Tripp Isenhour (69), Aaron Baddeley (70), Jason Caron (64), Brian Kamm (67), Omar Uresti (67), and Andy Sanders (68) are two shots back.
First-round leader Jason Buha followed an opening 62 with a 76 Friday and is in a group four back.
'This course is not that easy at all,' said Sheehan. 'I guess with the wind down and the rough not very high, you're going to have to guys play well. The trick is to do it four days in a row.'
Sheehan and Bugg tied Brett Quigley's 134 total a year ago when he went wire-to-wire in winning the $81,000 first-place check.
'My expectations this week were to get into the top 25 and get a spot next week,' Bugg said. 'I know I'm hitting the ball well. Yesterday I made a couple of eagles and shot 66 and that made me think that if I keep it up, I might have a chance to be up there on Sunday.'
Full-field scores from the Buy.Com Arkansas Classic