The Lothians star recovered well from his damaging 74 at St Andrews on the opening day, firing a four-under-par 68 at Kingsbarns.
But, with the excellent weather bringing a barrage of low scoring at all three of the courses being used for the pro-am event, he was still lying just outside the top 80 at the halfway stage.
Gallacher had three birdies and an eagle on his second-round card, the latter coming at the long ninth.
At Carnoustie, the toughest of the courses, he probably needed another 68, if not better, to be around for the final circuit on the Old Course tomorrow.
Dunbar’s David Drysdale was in exactly the same boat in his bid to make the cut in the event for the first time.
He had made an encouraging start with a 69 at St Andrews but undid that work with a 73 at Kingsbarns.
Englishman Tommy Fleetwood and Northern Ireland’s Michael Hoey led at the halfway stage on 12-under, one ahead of 2010 Open champion Louis Oosthuizen.
Spearheading the Scottish challenge with two rounds to go was Marc Warren on ten-under, with Fifer George Murray two shots further adrift.
Both Warren, a World Cup winner with Colin Montgomerie four years ago, and Murray, the 2010 Scottish Hydro Challenge, were in action at Kingsbarns in today’s third round.
“Kingsbarns is a tricky course and you certainly have to be accurate,” noted Warren.
“But my wedges have been good so far this week – the work I’ve been doing on them is paying off.”