A question of grammar came up with a teaching partner recently that I believe falls under one of the conditionals, but I am not sure exactly how the grammar would fit. The example sentence went something like this? "Stop or I shoot." The exact grammar would usually be "Stop or will shoot." But I believe the first sentence may be used for emphasis. In other words, the speaker is conveying that if the person does not stop, there is no doubt he/she will shoot. In other words "I shoot." as a statement of fact.
Am I correct?
What is the grammar reference?

Question

A question of grammar came up with a teaching partner recently that I believe falls under one of the conditionals, but I am not sure exactly how the grammar would fit.  The example sentence went something like this? "Stop or I shoot." The exact grammar would usually be "Stop or will shoot." But I believe the first sentence may be used for emphasis. In other words, the speaker is conveying that if the person does not stop, there is no doubt he/she will shoot. In other words "I shoot." as a statement of fact. 
Am I correct?
What is the grammar reference?