Blow-forward is a firearm operation type where the friction and pressure of the bullet traveling down the bore drag the barrel forward. This mechanism also requires that the remainder of the firearm recoil away from the barrel for proper operation. Due to the reduced mass of rearward-traveling parts coupled with the increased mass of the forward moving parts (barrel in addition to bullet and propellant gasses), recoil energy is significantly greater than other operating mechanisms. The barrel and spring are generally the only moving parts. The operation can be best characterized as a combination of recoil and blowback operation.