USP/HK45 Series Detent Plate Quick Swap by H&K 4 LIFE-
We will be performing a variant conversion on this USP .40 Custom Combat. The conversion demonstrated below is V1 to V9 (safety only), but going to V3 (decocker only) is performed in exactly the same manner only utilizing a different detent plate.
Step 1- Remove magazine and completely unload the pistol (this is always step one)
Step 2- Field strip pistol. Set aside slide with barrel and recoil assembly.
Step 3- Lower hammer. Pull trigger and gently lower the hammer with your thumb.
DO NOT let the hammer fly forward under it's own force.
Step 4- The only pin we will be moving is the Sear Axle (Part #24, 214101). The red arrow below indicates the Sear Axle. Note how the Sear Axle engages the notches in the top of the detent plate.
Step 5- Insert a punch down the channel in the frame that the ejector sits in. Use the punch to depress the Detent Slide (Part #36, 214105). You will feel this part under spring tension with the end of the punch. Pressing downward on this part will take spring tension off of the detent plate.
Step 6- With your thumb, depress the Sear Axle away from you until it clears the detent plate and is sitting flush with the frame. The Detent Plate can now be removed. It is not necessary to drift the Sear Axle any further then this. It is also safe to remove the punch (rest assured nothing will go flying out of the frame).
Step 7- With the detent plate now removed, you will notice the Control Lever (Part #33, 214184) has lost spring tension and is pointing downwards. Also note Sear Axle now sitting flush with the frame.
Return the Control Lever to the neutral (center) position and insert the new detent plate. The channel in the detent plate fits into a groove on the control lever. With the Control Lever in the center position, it will line up properly like this...
Step 8- Use the punch to once again depress the Detent Slide in the same manner as before. This will allow the Detent Plate to be lowered into position.
Step 9- With Detent Plate properly oriented, use your thumb to press the Sear Axle back towards you, causing it to engage the notches in the top of the Detent Plate. Push the Sear Axle until it is flush with the face of the Detent Plate. Remove the punch. The new Detent Plate is now installed.
Step 10- Check for proper function of the Control Lever (I.E. safety variants should have a working safety, decocker variants should decock, V1/2 should perform both functions)
Reassemble pistol, check function.
Done.
This post with pictures took a hundred times longer to create then to perform the actual conversion. :biggrin:
Disclaimer- I am not responsible for the use or misuse of the information contained within this post.
You are ultimately liable for any work you perform on your own pistol.