[Alpo]

Negative. They will headspace on the little lip, just fine. Howsomever, without the moon clip you have to either punch 'em out from the front with a pencil, or pick 'em out from the back with your thumbnail or pocketknife. The moon clip's real purpose is to let the ejector star push 'em out.

Very early Colt 1917s did not have the lip, and need the clips to work. Webleys don't have a lip, so if you have of them that has been shaved, it also requires clips. Smith, however, has had the lip from the beginning, and Colt went to it within about the first six months of production.