Shot some Blackhorn 209 this morning, 17 shots total.
I had run some alcohol through the bore and breech plug of my KP1, then blew it all out with air - or so I thought. Put in a partial charge of powder followed by one of the thick wads that I use, then seated it down tightly. Snapped a Winchester 209 primer on that squib load but the only pop was from the primer. I tried about 5 more of the W209s trying to get the charge to ignite with no success. Finally went into the shop and used compressed air to blow all that first charge out of the bore. Put another charge in the bore and got it to fire on the second primer. I had read that a fouling charge is needed with this powder but I think someone forgot to mention that charge needed to be a full load.
I was using a cylindrical flask with a 100 grain spout installed. A spoutful of powder was topped with a 200 grain Hornady XTP (10mm) in a blue MMP .50/.40 sabot. The rifle had only been boresighted since changing from a Sightron to a Leupold 3x9 scope, but I felt it would be close enough to start my shooting at 100 yards. It took a few shots to get the point of impact about where I wanted - roughly 2" above POA. Once there, I shot a group of five of the XTPs which opened dramatically with a "called" high shot. The remaining 4 shots in that "group" went into roughly 1.75". I then shot four of the more expensive TC ShockWaves of the same weight and in the same sabot type. Those four went into roughly 2". I was satisfied at that point with the point of impact for both bullets, the Shockwaves hit a bit lower than the XTPs but still close to that 2" high on average.
Being a person that likes to shoot cast conicals of pure lead, I decided to give a 440 grain .503 conical a try. In spite of reading reports to the contrary, I decided there was no good reason why a conical couldn't be fired with the Blackhorn. I switched to a 70 grain spout and load for the conical. I took careful aim at one of my upper targets, knowing the big conical would strike considerably lower than the featherweights I had been shooting. When the W209 ignited, there was a double stutter as the rifle hang-fired badly. Not only was there a terrible hang-fire, blowback into the KP1's action area (which had been nearly nil up to that point) was terrible. The plug now had a thin coating of carbon deposit on all exterior surfaces and a thicker deposit inside the primer pocket. The deposits were spread to the interior of the barrel around the plug and the face of the KP1 action, and in particular a heavy circular deposit around the firing pin area - just bigger than a 209 in diameter.
I decided to quit at that point as I had found out what I needed to know and by that time the humidity level was getting to me.
I was not satisfied with the groups I shot but I'm convinced a little tweaking of charge level will get me there with the sabot'd rounds. Conicals and the KP1 seem totally not made for each other. The newer hammer/trigger assembly now in the rifle has a trigger pull set considerably higher than I would prefer - something may need to be done about that.
I never swabbed the bore at any time during the session. Loading was consistently firm with the sabots from start to finish. Of course the conical loaded easily - too easily I guess.
There was very little smoke but I do get a whiff of odor from that smoke - not a bad odor, just an odor. The odor might compare to a faint hint of acetone. The conical round made cleanup take a bit longer than would have been the case had I not fired it, but it still cleaned up easily. I had only put tape on the breech plug and, as others have noted, the breech plug came out as easily as it went in. Pure alcohol is great to clean up the deposits left behind both inside the plug and elsewhere. The plug did have a pretty good amount of carbon buildup inside, especially after that conical shot.
All in all, I would say the cleanup was easier than it would have been with any other powder I have used.
My shooting was not at all impressive but by the end of those 17 shots, I was sweating like mad. It wasn't that hot out, but the humidity was torture. I think the KP1 is most definitely a sabot rifle and with a little tuning would be quite accurate with the BH209.
I will probably continue to use BH209 in that rifle and in my G2 Contender (which will be my next up to bat with the BH). Both those break-opens can be a chore to clean and the advantages of BH209 will be more appropriate for those two. My conical shooters will continue to get Swiss, T7, or Pyro.
