Seams are correctly marked, UV's are messed up I have retopologized a shotgun and marked all the seams where they are supposed to, and then Unwrapped it, and instead of getting nice UV's, i get this:



Here are the seams:




I have tried Applying the scale, Averaging Island Scale, Packing Islands, and minimizing stretch, and Smart UV Project, and Lightmap pack, all of which slightly helped, but not enough. What is wrong?
Those lines stretching from an island to another could be caused by a single missing edge mark, or that after doing the UV Map you picked up a couple of tris and turned them into quads and those triangles where from different sets of islands.