When rezzing multiple objects from another object,
all
scripts in that object are delayed by some variable number of milliseconds. This makes a lot of vehicle-based gunnery solutions untenable without very silly workarounds, such as temp-attach HUDs. This is a pretty bad bug that affects anything that has some amount of cooperative play of this nature. This also affects guns in general with at least three rez nodes, which can cause other inputs to be delayed for up to a second.
Some scenarios:
Helicopter has a nose gun, as well as two door guns. When the pilot fires the nose gun and at least one door gunner fires, all scripts in the object are delayed per shot. In this example, it is split into: movement, gun movement (for each seat), and rezzers for the guns.
Tank has a driver/operator and commander. Commander operates a smaller gun atop the tank. When the tank fires a canister (coalesced linkset "shotgun"), all scripts in the tank pause for about 0.25-0.5 seconds. When the commander fires at the same time as the driver/operator firing the coaxial (machine) gun, it causes massive event throttling on every script in the object, similar to the above.