The serial number on the rifle sent by Klein's to Oswald's PO Box is the same as the rifle found in TSBD.
There’s no evidence that any rifle went through the postal service, was delivered to Dallas, or was picked up by Oswald or anybody else.
Oswald's prints were found on that rifle.
No, there were some prints near the trigger guard that were unsuitable for identification purposes, and a single partial palmprint showed up a week later on an index card.
There are photos of Oswald holding that rifle.
No, there are photos of Oswald holding a rifle that cannot be uniquely identified to the exclusion of all other rifles.
There is no accounting for the rifle in Oswald's possession except as the rifle found in his place of employment.
The burden is on you to prove that it’s the same rifle, not on anybody else to prove that it isn’t.
On planet Earth, that is considered evidence.
On planet Earth, that’s called misrepresenting evidence.
It is of type used in any criminal investigation. It is hard to imagine how there could be much more evidence than exists to link Oswald to the rifle.
Why, you have no problem imagining all sorts of things. Imagine having any conclusive evidence of any of the above claims. For example, evidence that was actually properly collected, documented, stored, and secured.