I have not experinced that problem, and I don't dry patch the butter out of my encore after storage. I do however run 2 or 3 209 primers through mine which could take care of any excess butter.

Not questioning your shooting skill, but with an 8 inch miss after several good shots, is it possible that it was just a bad shot by you. I'll be the 1st to admit that while I am know to be a pretty good shot, I have been know to let a few fliers go that were nothing but my fault.