GB Hammer and Spring Installation: An Easier Way

Discussion in 'Other Handguns' started by rkmorrow, Aug 12, 2013.

  1. rkmorrow

    rkmorrow New Member

    Installing the hammer and hammer springs on the Steyr GB can be challenging because each hammer spring must be wound and its fixed (hooked) end inserted into a cavity in the underside of the sear (Figure 1). This can be done using some thin steel wire, a hook tool or dental pick, and a flat screwdriver for turning the grip screws. The method is shown for a GB with the later spur hammer. It should work for the ring hammer version as well but I haven't tried it. This was inspired by a previous post from Patm in Feb 2010 who used wire to hold the hammer springs in a different way. Thanks!

    Figure 1. Hooked end of a hammer spring fits into this cavity in the sear.

    Safety note: Since you are working with springs under tension, always wear safety glasses.

    Step 1. With grip panels removed, secure lower front of the frame in a soft-jaw vise. Tighten only enough to hold the frame securely and use care not to bend the frame. Leave the lower grip screw holes exposed. Install a grip screw about two turns into each lower hole.

    Step 2. Place hammer springs on the hammer studs in the orientation shown (Figure 2). The straight end of each spring fits behind the "tee" projection on the hammer.

    Figure 2. Hammer springs fit onto the hammer like this.

    Step 3. Install hammer pointing downward into magazine well with hooked end of each hammer spring pointing upward (Figure 3). If necessary, pull the trigger slightly to make room for the hammer to pivot into position. Install hammer retaining pin.

    Figure 3. Install the hammer pointing downward and the hooked end of each hammer spring pointing upward.

    Step 4. Cut two 18" lengths of thin steel wire and bend each length in half to form a loop. Insert the loop end of one wire into the frame's left magazine well cutout, route the wire in front of the hammer assembly, and place the loop over the hooked end of the left hammer spring. Wrap wire one turn clockwise around the left lower grip screw and tighten grip screw just enough to secure the wire. Repeat the process for the right hammer spring (Figures 4 and 5).

    Figure 4. Fit wire loops over the hooked end of each hammer spring.

    Figure 5. Wrap the free ends of the wire clockwise under the lower grip screw.

    Step 5. Rotate the hammer toward its upright "at rest" position. Adjust wire length through trial and error until the hooked end of each hammer spring is pointing slightly forward of the vertical when the hammer is fully upright (Figures 6, 7, and 8). The trigger arm will hold the hammer in this position. If additional wire length adjustment is necessary, the hammer can be released again by restraining it, pulling the trigger, and easing it forward. If the hooked end of the right-hand hammer spring becomes caught under the frame rail (Figure 8) pull it free with your hook tool.

    Figure 6. Hammer in its vertical position with wires holding the wound-up hammer springs.

    Figure 7. Left hammer spring in its proper orientation.

    Figure 8. Right hammer spring in its proper orientation.

    Step 6. Install the sear and sear pin (Figure 9). The hammer may need to be pulled back slightly during sear installation.

    Figure 9. Sear is installed and secured with its pin.

    Step 7. Remove wires from the grip screws and cut each wire to leave a short stub.

    Step 8. Use your hook tool to pull the wire stubs out from rear of frame (Figure 10).

    Figure 10. Removing wire stubs with hook tool.

    Step 10. Reinstall grip panels, cock hammer, and reassemble your GB.
    silentheart, ROBOCOP195 and Soverign like this.
  2. Syntax360

    Syntax360 Premium Member

    Wow, nice write up! I'm sure all the GB owners will appreciate the effort that went into putting it together.:cheers:

  3. dash

    dash Member

    That's pretty much how I did it, but used vinyl covered wire instead and wrapped the wire around the bottom of the mag well to hold the springs. Found out that a previous owner had the springs installed wrong...felt much better once corrected. Was a little harder to remove the bits at the top after clipping the wire, but my hands were much happier. Great write up for all those that may have to deal with this in the future!
  4. Soverign

    Soverign Premium Member

    Great write up for sure!
  5. babj615

    babj615 Premium Member

    This thread should be made a Sticky! :)
  6. blackjernej

    blackjernej New Member

    This is my recent accidental discovery. Hammer, sear and springs stick together by themselves.
    No tools required, put hammer (with springs loose) and sear like seeing on picture and push in the hooked side of a spring.
    You should end with all 4 parts hold to each other.

    I think this is the way, they met to be assembled. Try it and post reply. If this will work on other pistols, the biggest gb assembly problem is solved.
    silentheart and ROBOCOP195 like this.
  7. rkmorrow

    rkmorrow New Member

    This is very interesting. Can you insert the parts into the frame and install the pins? If so, this is far superior to a method that requires wire and tools.
  8. blackjernej

    blackjernej New Member

    It's actually the way I got it out of the frame after I removed pins.
    It works both ways in and out.
  9. jsavino54

    jsavino54 New Member

    Re: GB Hammer+Spring Installation: easy fixturing for spring winding and setting

    Here's an easy way: Use two slightly smaller drill bits just placed in the pin holes as a simple winding fixture. With the frame lying on its side, they will stick out quite a bit, and the frame holes will insure that they are spaced the exact right distance.


    With the frame laying on either side, insert a #32 drill bit (.116" diameter) with flutes down into the sear pin hole. This exact size will fit just a bit loosely and not cut into or mar the holes at all. Do NOT use 3mm or any size you have to drill in - the point here is to just fit, not to cut a larger hole.

    Then likewise insert a #23 drill bit (.154" diameter) into the hammer pin hole. Again, do NOT use 5/32" or 4mm drill bit has to be just a bit smaller than the hole.

    You then will have 2 parallel drill shanks sticking up a good distance out of the frame. These are the right size and the right distance apart to act as a fixture for winding your springs. You can tape these to keep them from falling out but I didn't find it necessary.

    Put the hammer, sear and springs on these and then wind up and set the springs easily with a forceps, needle-nose, or any tool of your choice (my fingers weren't quite strong enough). Make sure the sear is more or less centered on the hammer or else it will be tough to fit the assembly into the frame later.

    Carefully lift the wound-up sear & hammer assembly off of the drill shanks. It will stick together on its own. Be careful not to drop it or parts will fly!! Lay it down gently

    Then remove the drill bits and just place the wound assembly back into the frame. Slip both hammer and sear pins in from either side as far as they will go. This will hold the wound-up parts in place.

    Lastly, a bit of wiggling the hammer & sear will allow you to push the pins thru the far side. It's easy to see from the far side, which way to wiggle it.

    Voila! No wire, no special tools (other than 2 cheap drill bits). Happy tinkering!
    Last edited: Feb 20, 2015
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  10. 44hunter45

    44hunter45 New Member

    Thank You so much for this thread. I've only dared to get into the hammer group twice. This thread saved me and my GB/
    ROBOCOP195 likes this.