(CL 5th)
This +1 paper alchemical cartridge contains a bullet and is marked with a symbol of an ear. When fired from a firearm, a reporting cartridge allows the wielder to temporarily transfer her sense of hearing to the location where the bullet lands. Until she dismisses the effect by rubbing her ears as a move action, the wielder can hear as clairaudience from the square in which the bullet landed, regardless of whether it hit its mark.
(Scouting is worded identically, excepting being for the visual half of Clairaudience/Clairvoyance, of course.)
The way these items are worded, rather than using the range/duration of the spell Clairaudience/Clairvoyance in its spell description, might the range be simply wherever the firearm can reach with said bullet, and/or the duration being continuous up until ended in the described fashion?
The description of the effect occurring when/where the bullet lands might be intended to/capable of replacing the 400ft + 40ft/lvl of the spell, and the wording with regards to its duration being "Until she dismisses the effect..." might (and I'm actually rather partial to this interpretation) obviate the need to refer to the spell's duration due to being "as ___" spell.
For example, would a gunslinger with a rifle be capable of putting this bullet in a person/object up to 800ft away (max 10 increments of 80ft) and/or should the target move outside of 600ft (400ft+5(40ft)), would the bullet's effect still function? Then, if said gunslinger with said shot out and in effect should desire to continue to keep the effect running, might it still function for as long as he/she deigns not to rub their corresponding sensory organ?
If rule of cool ever should have its sway with this one, I could imagine something like a sniper on a navy ship putting one of these bullets into the frame of a pirate captain's cabin and keeping his sense of hearing slaved to it for days on end in order to try to track the ship's movements based on the captain and crews' conversations and orders.