The NSW Nationals are at risk of being "trumped" in Orange, with a massive primary swing of more than 60 per cent in some booths set to see preference votes decide the close race.

The Coalition partner is staring down the potential of a devastating loss in the byelection after voters in the central-west electorate turned away in droves on Saturday.

The figures on the NSW electoral commission website on Sunday morning show Nationals candidate Scott Barrett had won 29.4 per cent of primary votes but Philip Donato, from the Shooters, Fishers and Farmers (SFF) party which has never held a lower house seat in the state, is not far behind.

Mr Donato trails with 24 per cent of the vote but may claim victory thanks to Labor preferences.