Device for indicating low ammunition in a firearm magazine

A device for indicating low ammunition in a firearm magazine, comprising:

• a switch internal to a firearm magazine, attached to a magazine insert or a floor plate and situated so as to be responsive to a portion of a magazine spring;
• and
• an indicating device in electrical connection with the switch;
• wherein a position of the portion of the spring varies in response to a varied remaining amount of rounds in the magazine due to compression and extension of the spring;
• and
• wherein the switch directs activation of the indicating device in response to a range of positions of the portion of the spring corresponding to the remaining amount of rounds being less than or equal to a predetermined low ammunition count thereby detecting and indicating low ammunition.

A firearm magazine, comprising:

• a magazine case, a plate, a magazine spring and a follower;
• a switch secured to the plate and responsive to a portion of the magazine spring and to a spacing from the portion of the spring to the plate;
• a light secured to the plate, responsive to the switch and visible external to the magazine;
• and
• a battery contact secured to the plate for selectably powering the light;
• wherein the switch directs available power from the battery contact to illuminate the light for the spacing from the portion of the spring to the plate being greater than or equal to a specified trip point distance, thereby detecting and indicating a low ammunition condition.