I believe this is my sixth M-4 build? I'm going through my notes from my last builds and looking for parts etc. I am surprised I can't find a source for all the multi-turn Bourns P mount trimmers? I found the 100 ohm (3296P-1-1011) at Mouser but the 2.2K and 4.7k seem to be 6-9 week back orders? Anyone have a source for these? Most the other parts seem to be available.