Do you know what else is ridiculous about the paper bag story? Since it was supposedly just shipping paper taped up, why, when Oswald was ready to start assembling the rifle for his ghastly act, did he get all the rifle parts out of that bag without tearing it? It's not as though he would have cared. It's not as though he was trying to preserve it.
What would you do? You've got this long bag containing rifle parts- both large and small. Would you open one end and shake out all the parts? Or would you put the bag down and just start ripping through it? Why the hell would you care about preserving that bag? Why would you want to dump the parts out of the bag?
It was long, wasn't it? If you dump everything out, you've got a long way to go. Wouldn't it be faster to just tear open the bag? It's not as though it would have been hard to do. There wasn't that much tape on it. You would just spread it open. You wouldn't dump the stuff out.
The very intactness of the bag adds to the ridiculousness of the story.