I would suggest a perfect test would be to get somebody to take a rifle that was wrapped up in a blanket, place it (dismantled) into a bag, then take it out of the bag re-assemble it (with a dime coin) and load the rifle, then fire 3 shots with it, and then carry it 30 yd or so and throw it among some boxes.
Get that same man to wait 20 Min's or so, yes he could even wash his hands. Pick up a revolver, try to fire it! THEN do a paraffin test on his hands and face, then match it to Lee Harvey Oswald's tests and see what the results might be. I suggest a distinct difference.
Bern
This is all fine and good if any Mannlicher-Carcano could've done the job but, of course it couldn't. The Carcano model in question is not even a rifle. It is a carbine which is a low-powered, close quarters weapon. On top of that, it was known as "The Humanitarian Weapon" because it misfired so often. It literally has been called a better club than a gun.
The shooting was the work of a few high-powered, accurate rifles manned by trained and accurate assassins. To lay this at the feet of a poor shot like Oswald was, and then have him use a ridiculous weapon looks to me that, although he may have taken the blame initially, he was never to have kept the blame. The story they cooked up is so flimsy that I believe that possibly Oswald was going to walk and that plan was hijacked in the end. This, is lent some credence in that there is now believed to have been more than one Oswald and Richard Case Nagell was convinced Oswald(the one he knew) was an agent working for the Soviets. It's not a stretch to think this all could've gone wrong if one or more of the perpetrators felt threatened by the cover story.
Of course the part I've laid out stating Oswald may have walked is pure speculation on my part, but you've gotta wonder why they set him up with such a flimsy story.