I was under the impression that velocities could be matched with Triple Seven. BlackHorn's advantage being with heavier projectiles it out performs in the velocity department. And also.. is 100 or 200 fps going to break the bank? Maybe on some ways a certain bullet can perform its intended final act. But I've shot a lot of Triple Seven in my time and never worried about power. Although you might be right, as I do not own a chronograph. That is one final step in this sport I have not made.
As for duplex loading BlackHorn 209.. its not the fact it would make it go off that concerns me. Its the fact in example; Greg shoots a White Rifle and a Remington 700 rifle with #11 caps. This has an exposed breech. I would not feel right to encourage anyone with an open breech to "make" Blackhorn go off. If BlackHorn was able to bury a chunk of 209 primer into my forehead from a Black Diamond.. I sure would not want that small copper #11 cap exploding from the back pressure in front of my face. This is just my opinion and I could be over cautious. Also there would be a reason why the manufacturer does not promote the use of their product in open breech design rifles as well.