Weitzman’s affidavit was from SaPersonay - long after the Carcano seen being carried out of the TSBD was in evidence. The excuse he gave in his retraction was that he only saw it “at a glance”, but not only did his affidavit give a very specific caliber for the rifle, he also described the rifle, scope, and strap in quite a lot of detail for just a “glance”.
So how did Weitzman describe the rifle? In his affidavit, he said this: "The rifle was a 7.65 Mauser bolt-action rifle equipped with a 4/18 scope, a thick leather brownish-black sling on it."
And in the FBI report describing Constable Weitzman's excellent adventure, the rifle is described thus:
"a 7.65 Mauser bolt-action rifle which loads from a five shot clip which is locked on the underside of the receiver forward of the trigger guard. The metal parts of this rifle were of a gun metal color, gray or blue, and the rear portion of the bolt was visibly worn. The wooden portions of this rifle were a dark brown color and of rough wood, apparently having been used or damaged a considerable extent. This rifle was equipped with a four-power 18 scope of apparent Japanese manufacture. It was also equipped with a thick, brown-black leather bandolier type sling."
Most of the described detail is nothing that anyone couldn't pick up in Weitzman's putative glance. The color of the stock and it's well-worn, rough appearance are nothing that can't be picked up in that first look at the rifle. Same with the color of the metal -- it's a gun that happens to be imaginatively described as being a "gun metal color." Weitzman's attempt to be more specific does little better: "gray or blue" --he can't even settle on a particular hue. The sling is "thick," "leather," and "brownish-black," none of which require any study beyond that first glance to figure out. So far, we have a very generic, if well-used, rifle.
Here's where it gets interesting. He is fairly specific about the scope. It's 4 x 18, and of "apparent Japanese manufacture." So how would he have known? Easy. That information is printed on the scope in big white letters on a black background for easy reading:
Now, there's one particular feature of the rifle that Weitzman decided to call out. "A five shot clip which is locked on the underside of the receiver forward of the trigger guard." Kinda like this:
What you're looking at here is the action of a Mauser Model 1891, often known as an Argentine Mauser. The model 1889/1890/1891 Mausers (all essentially the same design) have that fixed single-stack magazine extending down below the forestock. They are the only Mauser rifles with that magazine configuration. The previous models had a tubular magazine, and later ones (from the model 1893 on) were made with a double-stack magazine that didn't extend beneath the forestock. And all of the 1889/1890/1891 Mausers were chambered at the factory in 7.65x53. Single stack magazines fell out of favor in the bolt action world in the 1890's. Most post-WWI designs were derived from the Model 98, including it's more compact, double stack magazine.
As I've said previously, the Argentine government began to unload it's old bolt action rifles for surplus in the late '50s. A lot of these rifles wound up in the US, where they were picked up by budget-conscious shooters. Someone who had run into an Argentine Mauser, but had no particular exposure to the larger world of surplus bolt action rifles, could easily have seen a Carcano with it's prominent single stack magazine and assumed that it was one of the Argentine rifles based on that feature alone. And once they decided that, they "knew" that the rifle would have been chambered in 7.65 Mauser.
Curry was forced to retract his statement that the FBI had prior knowledge of Oswald, but it was true.
I think it was something more like, Curry said that the FBI hadn't told the DPD about Oswald at one of Curry's impromptu new conferences. Then, news stories beganto appear regarding "sources in the Dallas Police" who claimed that the FBI admitted that they knew Oswald could be a threat, which is a bit different from what Curry told the press. Of course, that brought a on a mighty thundering cloudburst of wrath from The J Edgar. Curry wound up saying that the FBI had not told anyone in the DPD that the FBI considered Oswald a threat to JFK. The whole issue turns on a single conversation between Hosty and Revill. Revill always maintained that Hosty told him that the FBI knew LHO could be a threat. Hosty maintained until his death that Revill's accusation was simply untrue. If only someone had been there to film the conversation, like Alyea recording the discovery of the rifle! ;-P