Push-button grease gun barrel and method of use

A grease gun comprising:

• a body having a reservoir connection aperture including a plurality of body concentric grooves disposed to receive a snap ring positioned along the inner portion of the reservoir connection aperture;
• the body concentric grooves comprise an upper channel and a lower channel, the upper and lower channels in operational alignment;
• a grease reservoir in communication with the reservoir connection aperture, the grease reservoir having a reservoir groove in a portion of an outside surface of the grease reservoir complimentary to at least one of the body concentric grooves;
• the snap ring moveably connected to a user-operable push-button to adjust the snap ring to engage and disengage the snap ring with the grease reservoir;
• wherein the upper channel has a greater diameter than the lower channel and the snap ring moveably engages the lower channel to retain the grease reservoir;
• wherein the snap ring moveably engages the upper channel to enable adjustment of the snap ring to disengage with the grease reservoir groove;
• and
• wherein the snap ring moveably engages the upper channel only upon inward force applied to the push-button and bottom of the grease reservoir simultaneously.