The Last Round Indicator is a feature on a weapon which allows a tactical advantage due to providing a warning of an empty magazine/clip with one round left in the chamber prior to expending the last round and locking the slide/bolt back on an empty weapon. The user can reload with the weapon still loaded and not be vulnerable while empty.
The Last Round Indicator is an additional tool that indicates in any fashion to a shooter when he/she is about to run out of ammunition in their firearm. It has been done to several personal firearms so far and is pretty easy to Smith into a Gun. This site is deticated to showing others how to intrigrate this idea into their own operations.