Push feed and controlled feed

Push feed and controlled feed (or controlled round feed) are two main types of mechanisms used in firearms to describe how the bolt drives the cartridge into the chamber and extracts the spent casing after firing.

• The push feed system does not grip the base of the cartridge before the cartridge has been fully entered into the chamber, and therefore under normal operation requires the cartridge to be fully chambered before it can be extracted.^[1]
• The controlled feed system grips the base of the cartridge with the extractor claw before the cartridge is stripped from the magazine,^[2] and therefore makes it possible to extract the cartridge before it has been fully chambered.

The better of the two systems has been debated for over 50 years,^[3] with both systems having their own strengths and weaknesses. Some prefer the controlled round feed for hunting dangerous game, while others state that either of the systems can be reliable or unreliable,^[4] depending for example on the quality of the rifle and maintenance. There has been a trend that newer rifle models tend to have a push feed mechanism, while almost every modern semi-auto pistol has a controlled feed mechanism. A push feed system in most cases is cheaper to manufacture than the more complex controlled feed mechanism.