That's interesting , I've watched a handful of tear down video's and none of them had one. But I do see the odd pic on the internet where you can see the screws . I wonder if it has something to do with newer older models or the fact that I've seen it called a rock island arms tm22, a Canuck tm22, Derya tm22 , and a couple of others . I wonder if certain importers have there's with or without said barrel spacer.