User blog comment:Im1azy/THe jist of my chapter so far/@comment-2253300-20131106084427

Sorry, but there are a few holes with the idea. I can see what you are going for though. First off the latest Founding, that being the 26th, occured before the Tyranids began invading the galaxy. So a Chapter being created to fight them is out of the question. However that does not mean that you can't have a Chapter that is overly focused on fighting the Great Devourer. They can't be just about the Tyranids since having a whole Space Marine Chapter devoted to nothing but Nids would be a waste of valuable military resources, but specializing in Tyranids is doable. You should create a scenario in which these guys got screwed over by the Tyranids. Space Marines hold grudges, and that's the best way to get a Chapter devoted towards fighting a specific enemy. Also Space Wolves Successor Chapters are not allowed. You see the Space Wolves have been deemed incapable of producing stable Successor Chapter in canon.