Standard FCU to Manual Safety FCU Conversion

In case anyone is interested in converting their standard FCU to a Manual Safety FCU, I thought I would post the procedure for reference. I compiled this by synthesizing the steps from two videos by The Rogue Banshee - one video walks through assembling a manual safety FCU from scratch and the other video walks through converting a manual safety FCU to a standard FCU (I couldn't find a video to do the standard to manual safety FCU conversion). Remember that you will have to have a manual safety slot cut in your standard FCU and a manual safety notch cut in your grip module (or buy a grip module that has the manual safety notch). AB Prototype provides this service. AB Prototype will also install everything for you, but if you want to save some cost or just like to work on your gun, here is the procedure. I just did this installation on my P320 last weekend and it went well. I would recommend watching the videos as well.

P320 Standard FCU to Manual Safety FCU Conversion

For the below, Left refers to the side of the FCU with the ejector – as if the FCU were in the pistol pointed forward.

1. Remove trigger bar and trigger
2. Remove slide catch lever
3. Install a punch into the U-shaped slot that is in front of the trigger hole on the right side. Use the punch to retract takedown lever and slide the punch all the way through the corresponding U-shaped slot on the other side of FCU and leave it there for the installation. This keeps the takedown safety retracted to the rear during the installation and keeps it out of the way.
4. Using a pin punch, push out the safety lever pin from the right side. This is the pin that the takedown safety curls around. Push the punch all the way through the hole on the left side of the FCU, pushing the safety lever out of the FCU. This keeps all parts in alignment.
5. Install the Left manual safety lever from the left side, pushing the pin punch back out as you do it. Keep light tension on the punch to make sure the end of the safety lever remains in contact with the end of the punch – this will keep everything in alignment. Push the Left manual safety lever all the way through so the end pushes through the hole in the right side of the FCU.
6. Using a small flathead screwdriver, push the sear pin so the right side is flush with the side of the FCU. This is the pin that is up and forward of safety lever pin. This may take some fiddling and a little force. You might need to pull the takedown safety away from the side FCU on the left side a little bit to facilitate this.
7. Install the manual safety detente spring in the center of the slot in Right manual safety lever
8. Install the manual safety detente into the Right manual safety lever so the tab is facing inward, towards the FCU (once installed)
9. Rotate the Left manual safety lever so the lever faces forward (if necessary)
10. Slide the Right manual safety lever onto the pin of the Left manual safety lever that is sticking out of the FCU on the right side
11. Rotate the manual safety levers so the detente is at the bottom of manual safety slot in the FCU
12. Squeeze the manual safety levers together lightly from each side and push in on the detente until it snaps into place – the tab will snap into the manual safety slot in the FCU. Be careful here to keep a grip on the detente - if you lose your grip, the detente and spring could fly out under the spring tension and they are small enough they could be very hard to find again!
13. Rotate the manual safety levers so they are about halfway between safe and fire – this is to get the Right manual safety lever out of the way for the next step
14. Use a small flathead screwdriver to push the sear pin from the left side so it is flush with the side of FCU (i.e. putting it back to its original position). Again, this might take some fiddling and little force, but it will snap in to place.
15. Remove the punch that is keeping the takedown safety lever retracted
16. You're done with the installation at this point - check function by rotating the manual safety levers up and down to ensure they snap in to the Fire and Safe positions.
17. Reinstall the slide lock lever
18. Reinstall the trigger and trigger bar
19. Check function - rotate the manual safety levers up into the Safe position and pull the trigger. The trigger will move a little, but beyond that it should be blocked from moving rearward. Rotate the manual safety levers down to the Fire position and pull the trigger - it should function normally.
20. Install the FCU into your grip module and reassemble your pistol - check function again with everything assembled.

The safety functions by mechanically blocking the trigger bar from moving forward. This is accomplished by a small tab/notch on the Right manual safety lever that, when rotated upwards to the Safe position, fits into a slot on the trigger bar to prevent it from moving forward. In addition to the manual safety cuts in the FCU and grip module, following are the parts you will need:

• Manual safety trigger bar - this has become the standard trigger bar now for both the standard and manual safety FCU's, so you may not need to buy one. If you have an earlier pistol, however, you might have the original standard trigger bar version and so might need to buy the new version.
• Left manual safety lever
• Right manual safety lever
• Manual safety spring
• Manual safety detente