I happen to own an example of the HP9 that Marstar carried a few years ago (I don't know if they're still in stock) and I recently picked up the 780 Homeland Security model on sale from SFRC for $129. The picture at the beginning of this thread certainly looks like the older HP9 I purchased from Marstar.
The 780 model looks alot like an 870, but on closer inspection it becomes evident that it's much more roughly done, and that none of the parts are interchangeable.
The Marstar HP9 is much, much nicer, though I'd been told by the people at Epps that only the internals are interchangeable with the Remington parts, not the barrel. To test this, I tried putting my 870 smooth bore slug barrel on it and found that it wouldn't go in. That said, I tried the same barrel on a Canam Grizzly and it fit just fine.
Had I not already had about one two many of these short 870 clones, I would be awfully tempted by the shotgun advertised on this thread. If it can be confirmed that Remington barrels would fit (like on the Grizzly but not my Marstar HP9), this could be the best deal of all of the shorttie Chinese shotgun options unless you were dead set upon a 12" barrel, since it wouldn't take much to turn it into a deer or fowling piece.
For Your Consideration,
Frank
