To my knowledge, a .50 BMG round is accurate out of a sniper's rifle for about two miles. However, accurate shooting doesn't mean that's all the farther it will go, if you plan on testing this,...
I am assuming you are asking about the specialized case of it being fired on earth at sea level. If so, neglecting air resistance, a Barrett .50 caliber round fired on a flat plane at 45 degrees it...
In excess of 2 miles.
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The previous answer of 2 miles is a bit of crazy talk. If a .45 ACP handgun
is fired parallel to the ground it will...