For pistols, these actions are typically operated with the right hand. If you can click your middle mouse button left and right, try this:

Safety
Left middle-click - The less useful of the two clicks for a less useful action.

Auto Mod Toggle
Right middle-click - Sweep your pointer digit to toggle semi or auto. It's quick and "safe!"

If don't have such buttons:

Safety
Middle-click - It's like removing your finger from the trigger :)

Auto Mod Toggle
Bind adjacent to the Hammer key.


More actions typically operated with the right hand.

Hammer
This should be your primary thumb button. You can uncock by holding Hammer, then holding Fire, then releasing Hammer.

Slide Lock
Bind adjacent to the Hammer key. You can check if the chamber is loaded by holding this action then holding Pull Back Slide.


The last actions that can be operated with the right hand. If you can click your middle mouse button left and right, try this:

Swing Out Cylinder
Left middle-click - Swing left.

Close Cylinder
Right middle-click - Swing right.

If you don't have such buttons, I'd bind these actions adjacent to the Hammer key.

Removing the (magazine)(casings) from your gun so you can insert (another magazine)(more bullets). Whether you're talking about a semi-auto pistol or a revolver, that's how I look at it.

Extractor Rod
R - From my point of view, this is the main reload action for revolvers.

Eject/Drop
R - If magazine release were a separate action, it'd be on the right hand. Besides, how many people don't use R for reloading?


There's no reason for these actions to have separate keys.

Insert
E - Extract/Eject is right next to Insert. Cool?

Get
E - Why not?


Alt - It's nice having full movement controls with the ability to check the barrel.


Q or Tab - I prefer Tab, but the point is to have the bind on the same line as Insert.


Shift - May seem odd, but I treat crouch as both a movement speed and height toggle. It's also easier to spam than Ctrl.