It might look like i am picking on the Plunger Guns, I am HONESTLY NOT Doing that, Though I am honest in Saying that i personally don’t like the Plunger Guns, and will never own another. The True intent here is to show the importance of Getting in there and getting these Guns PROPERLY Cleaned, and what happens if you Don’t.
I have owned the MK-85, and have hands on experience with the Knight Bighorn (Basically the same thing as the MK) And i owned a White Super 91, Of these 3 Rifles, The Old White Super 91 Was my Favorite, and not just because it was a .451 (Though that did make a difference

) I personally felt the Sealed Bolt assembly of the Ole White S91 to be Superior to the MK and Bighorn, I found The White Bolt assembly MUCH easier to Clean/Care For.
One last note, After THOROUGHLY Cleaning these Guns it is important to Get them BONE DRY, I use a little Air Compressor with a Reduced Nozzle That allows me to “Pin Point” Air Flow, I can get in EVERY little Nook n Cranny and Blow it Dry, Now days you can own a little Pancake Style Air Compressor Cheap, and get yourself a Reduced Air Nozzle. My Handheld Steam Cleaner, and Little Air Compressor are 2 VERY used Tools in Cleaning my Blackpowder Rifles. Even the Rifles I bought Brand New, Look better today than when i bought them, My Rifles are METICULOUSLY Clean. And the Cool Part is, it is SUPER EASY to do with the Right tools, actually a pleasure to Clean