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They should but the indexing might be a little off. I traded the 14" bbl off my old HP-9 for a 12.5" DA Grizzly barrel with no issues. Claven2 posted a bit of info on fixing the indexing if it bothers you.
There was a thread recently where someone had to do a little machining to get an 870 barrel to index properly. Mine just fit fine. (Rifled factory 870 barrel onto an HP9)
Do you mean it would not go on at all, or that it was out of index, or that the action would not lock in battery?
I've never had a Grizzly or HP9 where a Chinese barrel would not go on nicely and lock up properly, in index. The majority of them will mount a Remington 870 barrel and lock up safely, but will be about 4 degrees out of index, requiring a 25 thou (or so) adjustment at the barrel indexing notch. This is not always noticeable without a vent rib, which makes the mis-alignment obvious.
Lots of people claim that the Rem barrels fit and index. Every one I have seen in person was out of index and the owner simply had not noticed. YMMV.