It's interesting that you should bring this guide rod question up!
There is a member (Don) over on
http://www.hs2000talk.com/cgi-bin/ubb/ultimatebb.cgi
who is making some one-piece, metal guide rods for our HS2000s and XDs. These are excellent quality. I just advised him yesterday that I believe there might be substantial interest by Walther P99 owners; I invited him to visit this forum and ask for himself.
I was quite surprised to find that when I tried one of Don's XD guide rods in my P99, it was almost an exact fit.
Currently, he provides the guide rod and a bronze washer that fits in the front of the slide's rod opening (this keeps the end of the spring from "snaking" through the opening)...you supply the spring. At this point, we XD owners, are using Colt Commander springs with 3 coils removed in the weight you choose (usually 18#, 20#, 22# or maybe even 24#).
Here's a picture of the guide rod and the bushing:
A 18# Wolff variable power recoil spring for a Colt Commander:
A comparison between Don's guide rod (right) and the factory unit (left):
The bushing is installed in the slide:
The guide rod installed:
A closeup of the guide rod:
The front of the HS2000/XD with Don's guide rod installed:
A view of Don's guide rod with the slide retracted:
I would encourage you to visit the HS2K/XD forum and you will find pictures and a lot of information. Check it out.
I believe Smith & Wesson also sells metal guide rods...sort of.