How to Install MP5 Bucking

Many air rifles are equipped with a Hop-Up, also known as "High Operation Power Up." This device acts in much the same way as rifling in a barrel of a firearm. The Hop-Up imparts backspin on the airgun ammunition resulting in greater accuracy and range. Hop-Up bucking is a small rubber tube that helps seat the Hop-Up mechanism onto the barrel. Over time the bucking can wear out. Installing a new Hop-Up bucking on a MP5 air rifle can be accomplished with little difficulty.

Things You'll Need

  • Screwdriver
  • Airgun cleaner
  • Silicone oil
  • Airgun grease
  • Replacement bucking
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Instructions

    • 1

      Unload the weapon completely. Visually inspect the chamber to ensure that no live ammunition is present.

    • 2

      Remove the front and rear take-down screws using a screwdriver. These are located on front of and behind the grip assembly. Separate the barrel assembly from the weapon frame.

    • 3

      Withdraw the barrel and Hop-Up assembly from the barrel assembly. Note that the Hop-Up assembly is attached to the barrel.

    • 4

      Remove the two screws on both sides of the barrel using a screwdriver. These screws hold the Hop-Up assembly to a bracket on the barrel. Slide the Hop-Up off of the barrel.

    • 5

      Slide the old Hop-Up bucking off of the barrel. Clean the barrel, inside and out, using proper airgun cleaner.

    • 6

      Note the groove on the underside of the barrel. A small lip on the bucking will slide into the groove for a proper fit. Line up the bucking with the groove. Apply a light coat of silicone oil to the barrel. Slide the new Hop-Up bucking into the groove and onto the barrel until it stops.

    • 7

      Apply a light coat of airgun grease to the exterior of the Hop-Up bucking. Reattach the Hop-Up. Insert the bucking into the Hop-Up chamber. Reassemble the weapon.