True. The fully integrated rail covering much of the top of the action is going to stainless steel like the rest of the action. That's probably +5 oz over an aluminum rail. Add in the full bolt knob, oversized shroud, etc and it totals up.
Pretty cool action for a heavy sporter though...60 deg bolt lift, integrated lug/rail, prefits to an existing group of prefits, stainless, nitride coated.....that's a lot for the price.