Poll Results 15

Here was the question:

Why is this sentence incorrect? Fired at close quarters, it was overkill.

Something is wrong with spelling or punctuation. 2 (3%)
Nothing is wrong with it. 6 (9%)
"It" was not "fired at close quarters." 50 (81%)
You can't use an "it" after a comma. 3 (4%)

So 81% were right: "it was overkill" is an expression in which the "it" doesn't refer to anything. However, "fired at close quarters" does refer to something, but it's not mentioned: a gun.
How would you rewrite the sentence?