The Trail Receiver is flat-bottom, constructed of alloy with 2 Barrel Retaining Bolts - one long, and one short, both the same thread-pitch. There was no thread-locker used on the Bolts - just some red lacquer on the Bolt Heads. The Torque spec is engraved on the Receiver itself - 5 Nm / 44"lbs - which actually seems scary tight on alloy threads, but whatever.... There is no apparent marking on the Barrel, Receiver or in the manual to indicate a specific order for tightening the Barrel Bolts. The manual does state that the Stock (Action) Screws are to be tightened beginning with the Rear (Trigger Guard) Bolt, but nothing about the Barrel Bolts themselves: