Sorry, I bought the complete firing pin assembly, my typo. Yes, it's just the guts in the bolt. It's the rear shroud, firing pin, spring, etc. It's sold as one unit for $65. The old one unscrews, the new one screws in. Just put a little grease on the threads. On all my new 700's, I take the firing pin assembly out and clean it really good before firing the first round. If you've never done that, you'd be surprised how nasty they're packed. I use non-chlorinated brake cleaner, a rag and a tooth brush.
No problem that's what I did. Works great. I clean the firing pin assembly every time I clean the rifle. I do that with my 1911's too.
