Three South Otago men heading out for the opening of the duck-shooting season on Saturday morning were processed for drink-driving and may face other charges.
But police say they are generally happy with the behaviour of those involved in the sport.
Senior Sergeant Richard Whitmore said 156 vehicles were stopped at a series of compulsory stops and breath test patrols in central Balclutha from 4.30am on Saturday.
Most vehicles stopped belonged to duck-shooters on their way to mai mais and ponds in the area.
The three drivers processed for drink-driving were likely to face charges relating to being in charge of a firearm while intoxicated.
Two were stopped in Balclutha early on Saturday, while the third was stopped in Milton later in the day.
Police also checked firearms licences and if firearms were safely secured in vehicles.
Some warnings about the safety and carriage of firearms were issued, but Snr Sgt Whitmore said staff were "on the whole, pretty pleased".
