I don't care what the parts are made of they aren't steel and no convincing on your part is going to make people that don't like that feature buy them. Have you ever heard of a steelbolt shroud or "bolt cover" break on a conventional rifle ? I'll bet not but I know of at least 2 people that have had that happen. One used to post here and there is a thread on 24hourcampfire talking about this same problem. A lot of people don't buy glocks because they are plastic/polymer and I don't like them for that same reason as well.