Wiktionary
unchambered
vb. (en-past of: unchamber)
Usage examples of "unchambered".
Then there was the air: limitless, breathable air, unchambered, unguarded.
An unchambered Bender might vibrate itself into another dimension, leaving a smoking crater a klick across behind it.
He slipped the clip from his big gun and unchambered the round that was in the receiver, then he emptied the cartridges out of the revolver.
This is the case with all the guns, chambered as well as unchambered, excepting the 8-inch shell-gun of 63 cwt.