Here is the full list of all 45 RUNNING WITH RIFLES achievements.
Destroy first prison bus/door
Kill 100 enemy soldiers
Win your first map of the campaign
Kill first elite soldier
Kill 500 enemy soldiers
Kill 1000 enemy soldiers
Died 100 times
Died 200 times
Died 500 times
Win the Greenbelts campaign
Win the Greycollars campaign
Win the Brownpants campaign
Destroyed the Darkcat tank
Roadkill 5 soldiers
Roadkill 20 soldiers
Roadkill 100 soldiers
Unlock the first enemy weapon
Unlock 5 enemy weapons
Unlock 10 enemy weapons
Kill 100 enemies with blast projectiles
Kill 200 enemies with blast projectiles
Kill 500 enemies with blast projectiles
10.000 bullets shot
50.000 bullets shot
100.000 bullets shot
Destroy 1 anti-air structure
Destroy 5 enemy vehicles
Destroy 10 enemy vehicles
Destroy 20 enemy vehicles
Destroy 2 enemy structures
Destroy 5 enemy structures and 1 communication structure
Destroy 10 enemy structures and 2 communication structures
Destroy 2 special crates and deliver 2 secret cargo vehicles
Destroy 5 special crates and deliver 4 secret cargo vehicles
Destroy 10 special crates and deliver 8 secret cargo vehicles
Stab 2, kill 10 with a suppressed weapon and spot 2 strategical enemy structures
Stab 5, kill 20 with a suppressed weapon and spot 7 strategical enemy structures
Stab 10, kill 50 with a suppressed weapon and spot 15 strategical enemy structures
Heal 1 wounded soldier
Heal 5 wounded soldiers
Heal 10 wounded soldiers
Kill 5 elite soldiers
Kill 10 elite soldiers
Destroy 3 prison bus/doors
Destroy 5 prison bus/doors