The 2 different bolt release configurations, top on side of rear portion of the action and bottom in front of the trigger guard.
Question - Did the newer bottom bolt release come to life as a result of the AccuStock aluminum block running along side of the action?

If that is correct then is it safe to assume that all factory rifles with actions that come with an AccuStock have bottom bolt releases?
And all factory rifles with actions that come with stocks different than AccuStock are top bolt release?

Or is that too much of a simplification?