Yes, I divined as much.
What I am suggesting is that since gunsmoke was present in Dealey Plaza in the wake of the motorcade, and gunshots were heard, but no rifle ever seen, by deduction I think a handgun might have been used.
Also, secreting a handgun to alongside the presidential parade route is a lot better idea than a long rifle.
Given the copious amounts of gunsmoke---Dealey Plaza "reeked" by one account---a snub-nose .38 makes sense, as they release the most smoke, muzzle flash and make the biggest bang. The revolver was very common at the time, with shoulder harnesses etc available. Hand-loading bullets is a popular past-time for .38s.
But hey, maybe the diversion was a gunpowder-loaded homemade firecracker. Firecrackers were first made with gunpowder.
My main point is that what happened on the Grassy Knoll was a diversion, intended to help assassins, 80 yards behind the president, to escape. It worked to a large degree. Maybe totally for all we know.
Given witness reaction, I think something happened, but there evidently was no shot at the president.
That leaves an intentional diversion.