The man was attacked on Saturday at Maddisons Rd and is in stable condition in hospital.
Officers searched a house in Ashburton used by the Mongols gang, police said in a statement today.
A 31-year-old Mongolian branch was charged with injuring with intent to cause grievous bodily harm and unlawful possession of a firearm.
He appeared in court in Christchurch today and was remanded in custody.
A 32-year-old botched Mongolian member has been charged with drug-related offenses and will appear in court in Ashburton.
The arrests come amid a nationwide crackdown on gangs, Operation Cobalt.
Police said they would not tolerate the use of firearms in the community and were determined to hold individuals and groups responsible for this criminal behavior to account.
“We believe a number of other people were involved in this incident and we are following several strong leads, with further arrests likely.”
Police are looking for information about a blue Holden Commodore and a car trailer in the Maddisons Rd area on the morning of Saturday, July 9.
Anyone with information that can help can call 105, visit their local police station or contact Crime Stoppers anonymously on 0800 555 111.