All we can do is speculate about when it was sighted in. However, your idea suggestion/inference) that it had to be within a month or two of the assassination simply isn’t reasonable.
It's entirely reasonable to anyone who knows anything about rifles, especially older rifles. I spent 21 years in the Army, and every time we would fire, we would first go to the "zero range" to sight-in/zero our rifles because a rifle can lose its zero even after routine handling for cleaning and rack storage between firings, and these were M-16s, not clunky Carcanos.
As I have said before in this thread, it is reasonable to believe LHO sighted the scope in at the proper distance (~100-feet) for the Walker attempt. That same sight-in distance would be just fine for the shots taken in Dealey Plaza on 11/22/63.
No, this argument is completely unreasonable. One, there's no credible evidence that Oswald fired at Walker. Two, the gunman who fired at Walker somehow managed to miss him even though he was firing from a level and supported position and was firing at a large person who was sitting down. Three, the best eyewitness said neither of the men he saw leaving the Walker scene resembled Oswald. Four, Walker himself insisted that the bullet recovered from his house was not a 6.5 copper-jacketed bullet. Five, before Marina was threatened with deportation, she repeatedly said that she never heard Oswald say anything about target practice and never even saw him holding a rifle.
Abortive? ABORTIVE??? Your hero and mine thought I had beaten it to death and beyond. In point of fact, your "known to be elsewhere" statement is completely false.
You again show you have no clue what you're talking about. You don't even know basic stuff. In fact, you don't even know your own side's talking points.
The Warren Commission rejected all of the Oswald target-practice sightings, including the Sports Drome sightings, as "mistaken" because they claimed Oswald was known to be elsewhere and/or that there was inconsistency in the accounts. Have you not read the Warren Report? Gerald Posner makes the same argument. Have you not read
Case Closed?
Following the WC's lead, your fellow WC apologists use the tactic of lumping in the Woods' accounts with all the others and then dismissing them as "mistaken." They also rely on FBI interviews where certain witnesses supposedly changed their stories or gave contradictory descriptions of the man, ignoring the numerous times when the FBI misrepresented what witnesses told them.
The only "imposter" sighting was because Price said September 28 at the WC (when Oswald was in Mexico City) when he had previously said October 26, which was in fact the first day the Sportsdrome (spell it right, willya?) opened. There was no sighting, imposter or otherwise, on September 28. Moreover, I specifically noted that the other sightings were on weekends (including the long Veterans Day weekend) when Oswald theoretically COULD have been there. The only halfway credible sighting, that of the Woods, was the Sunday before the JFKA - but Oswald would not even have known JFK would be passing in front of the TSBD and would have been using a different, sporterized rifle that belched flame and sounded like a howitzer. In short, even though I tried to be gentle with the goofballs and their sightings, the Sportsdrome sightings are almost certainly bogus, involving neither Oswald nor an imposter.
"Almost certainly bogus"? Oh, really? That's not what you said in your OP for your thread on the Sports Drome sightings. You first said that the sightings were reported by witnesses who seemed sincere and believable and who were interviewed by journalists who did not appear to have an agenda.
And you again ignore the fact that Oswald was known to be at his daughter's birthday party at the same time the Woods saw the Oswald lookalike at the Sports Drome range, that the Woods were solid and credible people (the father was a dentist), and that both Dr. Wood and his son independently positively the man at the range as Oswald when they saw Oswald on TV after he was arrested.
If you think the Sportsdrome discussion was inadequate, revive the thread with something that makes sense. Otherwise, do not take the name of The World's Leading Authority on the Sportsdrome Gun Range (as it says on my business cards and letterhead) in vain or God will punish you. Abortive? ABORTIVE??? Are you kiddin' me? (Jim Mora voice).
You don't like to admit when you're wrong, do you? When you started that thread, you clearly did not realize that you were talking about Oswald sightings (reported by witnesses
you said were sincere and believable) that occurred at times when the real Oswald was known to be elsewhere.
And when I pointed out this fact, you began royally back-pedaling, bobbing, and weaving, rather than just admit you'd blundered.
BTW, I don't think he sighted it in at all. I think he retrieved it as-is from the Paine garage and took his chances because the JFKA was a completely last-minute, what-the-hell operation. I never sighted in my 30.06 at all, after buying it used or in the two years I had it; when my brother-in-law test fired it before buying it from me, I held my breath as he took the first shot at a glass jug 100 yards away - and exhaled when the jug exploded.
Oh, boy. Well, you'll forgive me if I just don't believe you. Anyone who knows anything about rifles--and I spent 21 years in the Army firing rifles--will tell you that relying on "mechanical zero," i.e., not sighting-in your rifle, especially if it has been a long time since it was previously fired, is risky and unwise.
Furthermore, go read MSG Zahm's WC testimony about sighting-in the supposed Oswald Carcano. It was of such poor quality that it took 10 rounds to zero it. And even then, when Master-rated rifleman Miller fired three shots with the iron sights, they were his most inaccurate shots. 
