I think you are speaking the BS; they talk about cartridges and magazines that feed the bullets in.
Fine. The rounds have to pass through a barrel to get to a target, and the marking on those rounds show they passed through the barrel of the rifle found on the 6th floor.
I don't particularly understand the point on the magazine.
No, I apologize for being hasty, but on the other hand; the Walker shot is often linked up to two men;
“There were no eyewitnesses, although a 14-year-old boy
in a neighboring house claimed that immediately after the
shooting he saw two men, in separate cars, drive out of a church
parking lot adjacent to Walker’s home. A friend of Walker’s
testified that two nights before the shooting he saw “two men
around the house peeking in windows.” General Walker gave this
information to the police before the shooting, but it did not
help solve the crime. Although the bullet was recovered from
Walker’s house (see app. X, p. 562), in the absence of a weapon
it was of little investigatory value. “- Warren Commission Report http://mcadams.posc.mu.edu/walker.txt
More than one man? Then, there could be a conspiracy.