Update: Special thanks to Clicker, here on the board, for walking me thru this. So it turns out that these 9mm recoil rods with the whitish nylon rings are not identical to the German ones. The ends are shaped so that unless you happen to have a F style carrier ( my Coharie SD was updated years ago with a RCM F style ) you cannot force it inside a standard German carrier. My Coharie full sized 9mm was also upgraded years ago but with the standard German. To bring even more clarity to my original post: somehow my German 10mm recoil rod ended up in the SD sitting in the safe. Clicker quickly pointed out that the diameter of the 10mm was much larger and with less coils. The 9mm rods measure .313 and have 78-79 coils ( Spring wire is .041" ). The 10mm rod is .350 with 65-66 coils. Spring wire is .046". The 10mm F recoil rod is about .050 longer overall. On another note: these US rods have the allen screws on each end BUT they have square ends. Clicker easily cut a bevel on his to make them more HK'ish. After we discovered the difference in the shape of the nylon end rings Clicker was in his shop making some! It appears that my rod end screws were secured with Red Locktite. Before I was about to heat them up to remove the allen screws then replace the nylon rings I noticed that I had two different carrier styles. One of them fit right into the German and of course the other fit the F style carrier. I hope this makes sense and helps other clone owners. Big thanks again to Clicker!!