As it turns out, there are advantages to forcing a square peg into a round hole. Our new Gen-4 rifles introduce E² Extraction Technology, which features four channels along the neck of the chamber. What exactly does this do?
When a round is discharged, the neck of the cartridge case forms to the chamber walls causing it to “stick” in the chamber. This patented feature allows a small amount of gases to travel back along the neck of the cartridge case; breaking it free from the walls. In addition, these gases stop against the shoulder of the cartridge case pushing it away from the chamber walls. This is similar to breaking ice cubes off an ice tray.
This removes a tremendous amount of work that would otherwise be left up to the extractor. The extractor is now pulling on a dislodged cartridge case. Imagine the difference in towing a car in neutral rather than a car in park. With the addition of this feature, your extractor can last up to five times longer than it would in a standard chamber.