Re: Quick question, Savage 308 to 223
The "bolt block" he's referring to is officially called an "extended front bolt baffle", and it reduces the length of bolt throw for 204/223 rounds. This isn't necessary if feeding from a blind mag, but is helpful.
If you run DBM and AICS 223 magazines from a SHORT ACTION, the extended front bolt baffle won't let the bolt go far enough back to pick up a round from the magazine...so you use a non-extended (308) front bolt baffle in that instance.
If you are converting a LONG ACTION Savage to 223, then things are a wee bit more complicated but certainly no big deal.
As for the firing pin...I dunno, but its possible. When I converted my 110 in .270 Win to a 223 with an old long action .378 bolt head I started seeing pierced primers on moderate to hot reloads, never on factory loads. I switched to CCI-450s and haven't seen the problem again.