When TC went to the 'easy open frame' they started using two piece bolts. Make them easier to open by opening one half of the bolt slightly sooner than the other.
The original barrels all had one piece bolts. To get them to work correctly on newer frames you needed to get the two piece other wise you had to drive out the pivot pin to get the gun open.
The bolts were/are not the weakest link, one piece or two.