I believe the weapons lock you guys are referring to is the Targeting Computer. As far as I gather from the films and SW flight sims (X-Wing through X-Wing Alliance) it's not an automatically-aiming laser assist at all.
Basically you just have a targeting computer that lights up indicating the optimal time to fire your non-guided lasers so you can hit a target you're leading in your sights.
SW lasers behave like WWII machine gun fire for all instensive purposes, they're individual shots and have no guidance system like torpedos or concussion missiles.
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