I have 3 of the Lee case feeder set ups and just tried the bolts from all 3 of them... each one measures 2.75 inches of thread. All 3 of the setups are at least 8+ years old so maybe Lee made a change somewhere along the line.
I printed 2 of the App Bracket Main because I thought something was off... but the both measure 2.577 inches deep for the threaded portion of the bolt.
No biggie because a new bolt is only like $.35....