Gun

Go to Dodge City. Go to the lower part of the bridge. Follow the path on the other side to reach a beach cave. Look inside for a life power-up which will reappear over time after you leave the area. Note: The cave also contains ammunition and money.

You can make more money on the bounty hunter side missions by capturing bounties alive. When you find a wanted poster that offers more money if you capture them alive and are having trouble doing so, use the following trick. Kill all gang members or bodyguards (if any). If the bounty is on a horse, kill the horse. Get close and melee attack. This will stun the fugitive and present an opportunity to grab them using LB. Then, press X to subdue the fugitive. This awards you more money for each bounty. If you press LB accidentally and release him, you can try to melee him and grab him again. However, if you do this too many times or if he has been shot, you may kill him and get less money.

Hold (Dash) while repeatedly jumping your horse to travel about double the speed.

Successfully complete story mode to unlock Magruder's seven barrel Nock gun.

Defeat Hollister.

Successfully complete the Hunting missions.

Defeat Reed.

Successfully complete the Pony Express missions.

This is a list of all the achievements in Gun, and how to get them.

Card Shark - 40 points
Get 100% completion in Poker Tournaments

The Greatest Hunter - 40 points
Find and complete all of the Hunting side missions.

Bounty Hunter - 40 points
Find and complete all of the Bounty Hunter side missions.

Easy Difficulty Complete - 10 points
Complete the game on the Easy difficulty.

Magruder's Mine Complete - 70 points
Progress through the 'Magruder's Mine' level on any difficulty.

Across The Badlands Complete - 25 points
Progress through the 'Across The Badlands' level on any difficulty.

Attack the Fort Complete - 20 points
Progress through the 'Attack the Fort' level on any difficulty.

Save Soapy Complete - 20 points
Progress through the 'Save Soapy' level on any difficulty.

Defend the Hideout Complete - 20 points
Progress through the 'Defend the Hideout' level on any difficulty.

Escape From Jail Complete - 15 points
Progress through the 'Escape From Jail' level on any difficulty.

Stage Coach Complete - 20 points
Progress through the 'Stage Coach' level on any difficulty.

The Red Hand Gang Complete - 20 points
Progress through the 'The Red Hand Gang' level on any difficulty.

Steamboat Massacre Complete - 15 points
Progress through the 'Steamboat Massacre' level on any difficulty.

Hard Difficulty Complete
Complete the game on the Hard difficulty.

The Unrivaled Horseman - 40 points
Find and complete all of the Horse Challenges.

The Hunt Complete
Progress through The Hunt level on any difficulty.

Honest Tom Complete
Progress through the Honest Tom level on any difficulty.

Quick Killer Complete
Progress through the Quick Killer level on any difficulty.

Law and Order Complete
Progress through the Law and Order level on any difficulty.

Ambush the Train Complete
Progress through the Ambush the Train level on any difficulty.

Take Down Hoodoo Complete
Progress through the Take Down Hoodoo level on any difficulty.

Hollister's Fort Complete
Progress through the Hollister's Fort level on any difficulty.

Battle at the Steamboat Complete
Progress through the Attack the Fort level on any difficulty.

Escape the Ambush Complete
Progress through the Escape the Ambush level on any difficulty.

Professional Prospector
Mine every gold ingot in the West.

Keeper of the Peace
Find and complete the Keep the Peace side mission.

Every upgrade collected
Collect every upgrade in the game.

Professional Postman
Find and complete all of the Pony Express side missions.

Every weapon collected
Collect every weapon in the game.

Normal Difficulty Complete
Complete the game on the Normal difficulty.

Insane Difficulty Complete
Complete the game on the Insane difficulty.