Of course you can’t prove a negative. However, the probability that Oswald made those shots with that rifle is approaching zero.
Every claim made by the WCR has more holes than Swiss cheese and the rifle has the most. It frequently contradicts the testimony to be found in the Exhibits to the Report.
The testimony it wanted to hear was in the Report while almost all contrary testimony (and there were hundred of witnesses who saw different sights.)
Most witnesses at the time stated the shots came from the direction of the sixth floor school book depository. Two of Oswald’s coworkers on the fifth floor heard the sound of a bolt action rifle being worked above them, and spent shells hitting the floor. Another witness saw the rifle barrel extending from the sniper’s nest.