SKFooter, Will recommended a 675 for Invector+ barrels and the Winchester SX3 specifically. I was not going to argue with that man at all. However, Clark, AllAboutShooting, recommends a 640-643 exit diameter. And he actually helped on the gun from the inception of it. So I think there is a couple different sweet spots to look for. Right now I think the Sumtoy is going to throw some great numbers once a deep clean, nice day, and optics are installed
D.Winsor. Dude, all I can say is this is my favorite shotgun I have owned. Went from a couple 1100s, M3500, 835, A5 and it is my favorite. Not to say those guns I mentioned are not absolutely great in their own right. This gun just fits me. Like I said though, those Win Supreme High Velocity w/ 1300fps kicked like a mule. I was bracing up for some heavier recoil on the LongBeards and it felt like a butterfly. I cannot stress how surprised I was about the recoil.
I have some MagBlends around here somewhere and I am going to test those out as well but I believe I am just going to stick with LongBeards this year since I have a couple boxes.