In short, yes you can mount a scope on a 1911. There are a few different ways to do it, but the most popular method is to use a Picatinny rail that attaches to the dust cover of the gun. This gives you a solid platform to mount your scope on, and it's also low-profile so it doesn't interfere with the gun's normal operation. There are also companies that make special mounts that go inside the gun's slide, but these are less common and usually more expensive. Whichever route you choose, just make sure that your scope is properly sighted in before you take it out to the range!