How could you not tell? Do people not look at the barrel where it locks up with the slide and on the hood and the feed ramp when they're looking at buying a gun? It's pretty easy to tell if it's new or if it's been fired a few times.
If you've sat there and racked it 100+ times, yes. A few times, probably would still look pretty much factory fresh since they're test fired at the factory.
Those shields are pretty stiff. I remember it being one of the harder handguns I had to rack. It's just got a stiff recoil spring in it. My G43 is a lot easier to rack.
I'm skeptical.