How to Bend an HK Receiver Flat

HK, otherwise known as Heckler & Koch, manufactures a variety of firearms, particularly high-end pistols and assault rifles. For those assembling weapons at home or for the gunsmith acquiring parts from HK, the rifle receivers come shipped flat. The flats must be bent in half to form the receiver body. After bending, the receiver body is generally welded together then drilled and tapped for accessories. In order to bend a stock HK receiver you'll need a few gunsmith and machine tools.

Things You'll Need

  • 6-inch-wide padded gun vise
  • Aluminum scrap block
  • Hammer
  • 3/4-inch rod or pipe
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Instructions

    • 1

      Open the padded gun vise to 6 inches wide. Set the receiver flat square between the vise jaws.

    • 2

      Lay a piece of 3/4-inch pipe or drill rod onto the center of the flat as it sits in between the vise jaws. The rod needs to be parallel with the jaws.

    • 3

      Position a square block of metal (aluminum scrap) onto the rod at the center. Push down on the block to apply downward pressure to the rod, which will hold it in place.

    • 4

      Tighten both sides of the vise by a half turn at a time each while holding the rod in position on the center of the flat. The receiver flat will begin bending up, and the rod will hold its center in the correct position within the jaws.

    • 5

      Strike the aluminum block against the rod with a hammer beginning in the middle and working down to one end of the now partially bent flat. Work back down the other direction, striking the rod along its full length. This will ensure the flat is bent proportionately along its length.

    • 6

      Tighten the vise until the receiver flat closes up completely in the vise. You'll notice a small seam between both sides of the bent flat. The seam will need to be compressed to flush later then simultaneously welded.