-As he is wearing armored platying, Magruder is impossible to kill by shooting him. Thus, use the bow with exploding arrows. First, get Magruder to chase you. As you are backing away from him, shoot an arrow at a geyser as he's walking over it. The flammable gas coming from the geyser will explode and critically damage Magruder. Once he is on the higher level, shoot him in the face with the rifle until he yells, then get into quickdraw mode. Get ready to shoot the big package of dynamite when he throws it. After shooting a few sticks of dynamite, the roof will collapse and crush him.
-Simply remain crouched as Magruder is unable to see you and thus becomes very vulnerable to sneak attacks. Keep reloading the whisky and fire arrows for an easy completion.
-The easy way to defeat Magruder during the second part of the Mine Mission is by standing beside each pillar. Stand by the left one. When Magruder throws dynamite at you, he will blow up the pillar. Do the same for the pillar on the right. This also works when blowing up the two remaining boulders. Note: Shoot Magruder in the head to get him to throw the dynamite.
-While fighting Magruder, run around away from him. When he walks over one of the circular areas, throw some dynamite over it to ignite the gas and damage him. Do not shoot him as he has metal armor and you'll just waste your ammunition. Throwing dynamite works, but the loco dynamite arrows work better.
-When Magruder gets up on the balcony, run up directly in front of the balcony instead of using your Quickdraw to shoot the big pack of TNT. When Magruder throws the TNT, it will go up, bounce off the ceiling, and land directly next to him. This makes this part of the fight much quicker to complete.
-Use Coles dad's rifle to shoot him in the head and anger him, causing him to throw a bundle of dynamite. Then, use the dual Peace Makers Hoodoo drops to Quickdraw it. This will knock down a pillar. Repeat this several times from behind a rock so he cannot hurt you.