I were to replace the #11 nipple on my inline muzzleloader with a 209 primer adapter, what sort of change, if any, would I need to make to the hammer to make it work?
Funny you should mention that. I have been making white powder with KNO3 and sugar that I shoot in my .50 cal muzzleloader. It is really inexpensive and easy to make, but it is also harder to ignite. With a standard #11 percussion cap the chances are about one in three that it will fire, but I have been making it work by "priming the load" with a few grains of Pyrodex. I tried loading the white powder in my 45 ACP. I put together 10 rounds and every shot fired with large pistol primers.There's really no need for them if using conventional muzzle loading powders with such a small chamber.
My .50 is a CVA.