It isn't. He had to sign for it when he picked it up, face+name-signature
Did he? Where is this signed receipt?
No one at the post office remember Oswald collecting a big heavy package, let alone a rifle that day ... or another day.
The Carcano is also the kind of rifle Oswald would have bought due it it being Italian and playing into his fantasies of being a revolutionary.
It was a fascist weapon, yes. Oswald was supposed to be a marxist?
That same add for the Carcano featured M-1 Garands for only a few bucks more, and this was a rifle he'd qualified on in the USMC. He didn't buy one because the M-1 was boring.
Well, if he was a kook, any less obvious explanation would do. How convenient.
See, now you're trying to play both sides.
No, I'm trying to show that the paper trial was a fabrication, but a sloppy one.
There are as many as 20 people who saw Oswald with the rifle starting with his wife who photographed him - twice - with it and the hand gun he used to kill Tippet.
Marina was and is not a trustworthy witness.
His Neighbors in New Orleans,
What neighbours? Name one.
and the men at the firing range are also witnesses to the rifle being in his possession.
The W-commission came to the conclusion that he couldn't have been on that firing range, and that the witnesses had to be mistaken.
Then there's Buell Frazier, his neighbor, co-worker at the TSD, and the man who drove him to and from the firing range.
When did Frazier see the rifle?
Not according to the fabricated paper trail, no. The only witness is Marina and she is not trustworthy.
First off, if they wanted to frame Oswald then planting a rifle he owned at the crime scene makes better sense than planting a random rifle with a fake paper trail.
And if he owned NO rifle?
As I've already pointed out, Oswald qualified with the M-1, so why not link him to a weapon he was trained to use without a scope? Why an oddball choice like the Carcano?
Don't know, but a qualified guess would be that it was cheap, foreign and sold only through post order, making it ideal for creating a false paper trail connecting Oswald with the murder weapon.
Your theory falls apart when the details don't add up.
So far so good?
The next problem assumes that "They" knew JFK was going to be in Dallas at the same time as Oswald,
Yes, Oswald was sent from Fort Worth to Dallas to New Orleans, and back to Dallas to a workplace perfectly located on the presidential route.
and that "They" knew it wasn't going to rain during the motorcade (it had been raining in Dallas and there was a good chance the roof would have had to be installed on the President's limo, and that wasn't decided until JFK arrived at Love Field).
It had been a bit more difficult with plastic transparent bubble yes, but still no critical obstacle, no. And, they could have had back up plans with different people, different city and ways to do it.
Three almost identical scenarios was aborted in the last hour in Tampa, Miami and Chicago the weeks before Dallas. Who knows how many alternatives they had in store should Dallas go wrong.
Too many variables to plan this shooting the way it was executed. Especially when in a month JFK would be at the family home in Hyannis for the holidays, where a competent shooter would have plenty of time and opportunity to shoot a less mobile target.
You do not know enough to speculate "easier ways" or more "rational ways". The conspiracy could be operating on different possible scenarios and on different levels of the organisation.
The shooters and people on the ground maybe thought it was part of a false flag operation against Cuba, making possible a full scale american invasion of the island. The people higher up maybe went for a less risky solution, going for the Lone Nut scenario.
Remember, if you are in control of the media and the investigation it doesn't matter how sloppy the cover up is.