If you've followed the classifieds and auctions much at all, you will invariably come across this expression in a gun's description. Sometimes it means that the gun shoots harder than a Red Ryder BB gun and sometimes only that the gun makes a loud noise when cocked and fired without a pellet. I've seen all definitions. After coming across "shoots hard", again, today, I was reminded of my favorite "shoots hard" true story. Sometime back in the 1950's, a fellow brought in a surplus WWII rifle to have it looked at. He said that, basically, he had gotten several deer the past few seasons but none this year because it just "shoots too hard". When asked what he had, the owner replied, "One of them Jap guns what been converted to .30-06 'merican." When the gunsmith examined the rifle, he found it to be a Japanese Type 38 Arisaka bolt action, the chamber reamed out for .30-06 but the original 6.5mm barrel still on the gun. The guy was shooting 150 grain FMJ ball, sizing down the .308 slugs to .25. I imagine it did "shoot hard", indeed!
