When it was "used"? How about when it went bang, bang, bang and shot JFK? Good grief. Witnesses saw a rifle in the 6th floor window at the moment of the assassination. A rifle is found on that floor with fired bullet casings from that rifle by the window and you are suggesting there is doubt about whether this rifle fired the shots. Hilarious.
No, I am suggesting that you favor jumping to conclusions on the flimsiest of evidence.
When it was "used"? How about when it went bang, bang, bang and shot JFK? Good grief. Really... You are certain that happened?
A rifle seen in the 6th floor window and
a rifle found on the 6th floor....And superficial as you are, you think it's as easy as 1 + 1 = 2, right?
A rifle is found on that floor with fired bullet casings from that rifle by the window and you are suggesting there is doubt about whether this rifle fired the shots. No, Sherlock, I am suggesting that if the rifle was planted the shells were likely also, don't ya think?
Which leaves us with two possibilities; (1) the MC rifle was used and the shells were fired on that day or (2) the rifle and the shells were planted on a staged crime scene.
Investigation is a process of elemination, which means that until you can eleminate the second option, you can't make any kind of claim about option 1.
So, what justifies the question? The rust in the barrel of the MC rifle, that would have been gone after the first shot, was still there. But I'm sure you can explain how this particular rifle was fired without the rust being removed, right?