Called Sig last week and asked about this, I ended up ordering a new guide and spring just for my own piece of mind. The shipping invoice says "recoil spring guide, 228, 229, 250C-40/357, METAL". The spring apparently comes from the 9mm version of the 229. I swapped it into my gun and worked the slide (unloaded of course) a few times. The spring feels a lot stiffer than the one it came with, but then I haven't had time to put 350 rounds through it with the new spring, so it might just be the lack of wear on the new spring. When I called the service rep insisted their metal guide rod only came in stainless steel, but when I opened the package today it had a black finish on it, which matches my gun. If you're interested, the two parts together set me back $20.76 (US dollars, just in case anyone assumed I was Canadian or Australian), although if your original part broke, I have a feeling they might give you the replacement for free. Mine was still fine, so I have no problem having paid for a spare. The rep did say the shipping was usually about $15, but he waived it without my ever saying anything about what an insane rip off that would have been.