2-piper...thats a good question...I don't understand either..I base my idea of demi-block on the Sauer and Pieper patents and those unappealing robust shotguns where Manufrance plugged 16ga tubes into a 12ga block...Have you seen those clunkers? If I bought a gun as chopper lump and a demi-block arrived, I would send it back...My first responce to reading that was...it's an error in translation and I know better...but how can I second guess FN...How can a demi-block also be chopper lump? what would be the point of splitting the block...I say we get a good look at sxsman's FN...look at the lumps to see if they are split, and look at the tubes 3 inches from the breach, to see if, in fact, it's a demi-block...send me a blank email with the subject as FN and I will send you those pages from the catalog...then we'll scrutinize his FN...hows that sound?