Wiktionary
adv. A method of aiming an artillery piece with the target in sight, as opposed to indirect fire where the target is not visible.
Usage examples of "over open sights".
Five minutes later, he had been back on his gun, rock like, unflinching, as he pumped shell after shell over open sights into the torpedo bombers.
His guns were firing over open sights, trying to suppress them, which meant that they had to more or less ignore the steady flow of men over the embankment and into the open groundalthough, thank the Spirit, they had knocked out the brace of pom-poms there.
Firing over open sights, a young sergeant hit a bomber just dropping its load.
But the others were firing, belching knives of orange flame over open sights as they came to bear on the Colonial armor.
At five hundred yards, over open sights, the gunners could not miss.
The woods here grew close to the railbed, so close that the Yankees could retreat to the tree line and still fire over open sights at the rebel position, and once back among the trees they poured an immense fire at the embank-ment.
As it was, each tube was firing under independent control-over open sights.
The ship had been prepared, perfectly positioned and the commander, firing over open sights, had let fly with all eight barrels.