What steps will reproduce the problem?
0. Roll a Hunter to a high enough level that you can put at least one point into Master Marksman
1. Bind the Aimed Shot ability to a key or mouse button. I use mouse5
2. Fire Steady Shot until the "Ready, Set, Aim" buff hits 5 stacks, proccing the free, instant Aimed Shot
3. Press your binding for Aimed Shot

What is the expected output? What do you see instead?
Expect that Aimed Shot will be cast instantly, costing 0 focus as the tooltip for Master Marksman says it will.
Instead, I see a cast bar of varying time length, based on my current haste rating, and I see that once the cast finishes, I continue to have the same amount of focus as before I began the cast; so the ability does cost me 0 focus, however it also has a cast time.

What version of the product are you using?
The Latest on Curse

Do you have an error log of what happened?
No

Please provide any additional information below.
Let me know what you need, I will test all you want

I've reported the problem to Sliczzarf