Here is the full list of all 81 Lead and Gold - there are Gangs of the Wild West achievements.
Kill a developer.
Win 100 powder keg matches.
Play all release maps.
Destroy 180 Objectives.
Win 300 Matches.
Destroy 60 objectives.
Destroy 60 Objectives.
Destroy 20 Objectives.
Deliver 720 sacks of gold.
Win 100 matches involving sacks of gold.
As the Gunslinger, deliver 3 sacks of gold and kill 12 enemies in a multiplayer round.
Deliver 180 sacks of gold.
Collect 8 sacks of gold in a Goldfever (COOP) match.
Win 30 matches involving sacks of gold.
Deliver 4 sacks of gold in a single multiplayer round.
Deliver 30 sacks of gold.
Be the player delivering the most sacks to base during a round. Repeat 3 times.
Conquer 720 zones.
Win 100 conquest matches.
Win 100 matches.
Win 30 conquest matches.
Conquer 180 zones.
Conquer 30 zones.
Tag 800 enemies.
Kill 25 enemies with the coach gun in a multiplayer round.
Trap 720 enemies.
Kill 3 enemies caught in your traps during a multiplayer round.
Kill 720 enemies with dynamite.
Kill 2000 enemies.
Kill 180 enemies with dynamite.
Kill 6 enemies caught in traps in a single multiplayer round.
Killl 30 enemies with dynamite.
Kill 15 enemies with dynamite in a multiplayer round.
Trap 180 enemies.
Trap 30 enemies.
Die 300 times.
Shoot off 250 hats.
Kill 1000 enemies.
Die 150 times.
Tag 250 enemies.
Kill 180 enemies with your sidearm (Gunslinger's revolver not included).
Shoot off 100 hats.
Kill 60 enemies with your sidearm (Gunslinger's revolver not included).
Tag 40 enemies.
Kill 300 enemies using fanning.
Kill 900 enemies using fanning.
Revive 720 gangmates.
Finish off 20 knocked down (KD) enemies in a single multiplayer round.
Kill 20 enemies with your sidearm (Gunslinger's revolver not included).
Finish off 10 knocked down (KD) enemies in a single multiplayer round.
Perform 10 headshots with the Buffalo rifle in a single multiplayer round.
Kill one and only one of each archetype in a row (without dying)
Catch 10 enemies in your traps during a single multiplayer round.
Kill 250 enemies.
Play a multiplayer round without getting killed or knocked down and kill at least 4 enemies.
Play a multiplayer round without getting killed or knocked down and kill at least 8 enemies.
Kill 50 enemies using fanning.
Rack up 30 kills in a multiplayer round.
Rack up 20 kills in a multiplayer round.
Kill 20 enemies with fanning in a multiplayer round.
Win a match.
Shoot off 15 hats in a multiplayer round.
Kill 3 enemies with a six shooter without reloading in a multiplayer match.
Perform at least 8 head shots in a single multiplayer round.
Kill 7 enemies with headshots in a row (without dying)
Score a long range headshot.
Shoot off 20 hats.
Perform a Grand Slam (kill 4 players within a short amount of time) in any multiplayer match.
Kill 3 enemies with a single dynamite blast.
During a multiplayer round, gangmates kill 10 enemies tagged by you.
Tag 20 enemies during a multiplayer round.
During a multiplayer round, teammates kill 5 enemies tagged by you.
Kill 3 enemies within 12 seconds using fanning.
Shoot off 4 enemy hats in a row (without dying or killing them)
Revive 180 gangmates.
Kill an enemy.
Attain rank 9 in a multiplayer match.
Revive 30 gangmates.
Revive 12 gangmates in a multiplayer round.
Revive 5 gangmates during a single game round.
Revive a gangmate.