Hi my first post after my intro and it's a question. I have just obtained my first muzzle loader here in the UK it's a 16 gauge Birmingham double gun and I intend to shoot it .It's 200 years old and in excellent condition. Question is the touch holes in the nipples are badly blocked and I intend to drill them out. What size drill do I use please? Not much black powder shot here in the UK It's classed as anti social and expensive! BUT lots of lovely guns available.