1- I never talked about penetration and range, it's normal that a slower bullet has less energy. 2- The chambers in the suppressors are quite resistant. The those I have used were made of metal. Here's a quote from Brügger & Thomet, one of the best manufacturers: "Q: Does my suppressor only work with subsonic ammunition? A: Most of our suppressors work well with regular ammunition but to get the optimal performance subsonic ammunition is recommended. There are exceptions to this that are clearly marked. When using regular supersonic ammunition, the supersonic crack will remain audible, but the operator won't risk hearing damage or betraying his position to hostile elements."