It is well known that KelTec RDB firing pin is a piece of CRAP!!! It breaks and therefore you can not use your rifle any more.
The issue re-view is available here https://bullpupforum.com/index.php?topic=10908.0
In US you will have the official support,but what to do if you are not in USA?
You can restore the firing pin functionality!!!!!
1) Get a 3D printer access with perfect geometrical alignment. It is VERY important to have less than 0.1mm print tolerances!!! 2) Print the kelstrikerfix1.stl file with the following params: - Nozzle 0.4-0.5mm - Layer height 0.2mm (0.3 will work too but print tolerances increase, which is not good) - use PLA+ plastic for better thermal performance
3) Fill in the matrix with WD40 and use your finger tip to pump WD40 into the inner chips+oil pocket 4) Use 1mm drill bit to clear the centering shaft. 5) make your broken firing pin tip flat. Use 1500grit sandpaper. Be patient and slow. All the process depends on how flat the drilling surface will be 6) Hammer the broken firing pin flat into the matrix. 7) Start drilling the hole using 1mm drill bit. GENTLY!!!! Medium RPM. Do not go forward with one push. Drill 0.5mm deep then clean and spray the drill bit with WD40. Avoid heating the matrix!!!!! 8) Once you have 5-7mm deep, You can use pliers to destroy the matrix. 9) Use the vice to fixate the firing pin (do not forget to wrap it with paper for protection). 10) Continue drilling with 1mm drill bit to 12-15mm deep 11) change the drill bit to 1.3mm and drill the hole bigger and deeper to the center of the firing pin. MEASURE the hole depth!!!!! 12) Your hole now is approximately 1.45mm in diameter. So now you can start placing in the new firing pin. 13) Take 1.5mm XSS steel drill bit (or any other fast cutting). Place it into the drill so you can access the length of the drilled hole. 14) Use the sandpaper to sand the drill bit tip just enough to enter the hole drilled in the firing pin 15) Now you can use hammer to insert the 1.5mm drill bit into the firing pin hole. GENTLY hammer till you have placed the drill bit all way the drilled hole. Try not to bend the drill bit! Use your measured value to check the depth. When you are finished, just add two-three more strikes just to be sure that you have placed the firing pin insertion all way down the drilled hole. 16) Now you need to sand the firing pin tip till you have about 2.2mm of striking tip. 17) Make your firing pin tip surface rounded.
Matrix is intent to be ONE TIME use. DO n0ot reuse!!!