You could, and a fabulous pistol they are, but not easy to shoot accurately. Don't get me wrong, I will never get rid of mine but the OP sounds like he's just starting out, and starting with the HW45 with open sights is definitely "the hard way".
Still, if he can master it, he'll know he can shoot a pistol.
Webley Genesis? Not heard of that one. I googled it and the nearest I got was Genesis playing at Wembley!