Travis,
Had not thought about the silencer issue. That would be a bad mama jama in .44. 300 grain Keith bullet at 800 fps would make a heck of a meatpole filler, if it will cycle them. Where legal ofcourse.
My friend and I built one. (His money, my support) it was a beautiful, beautiful thing.
240gr going 950 fed great, absolutely silent, and plenty deadly.
I believe we tried the 300's but they would not stabilize in the factory tube. His was fully suppressed, not a can, and he saved a few bucks using the factory tube. If I do one, I would go with a Douglas and faster twist.
Travis