Hi Dinny,
The 45-70 is way overkill on a critter like a raccoon and could ricochet a long distance after passing through the body. Use a .22 with CCI stingers or Rem Yellow-jackets.
A center-fire option would be any 224 cal with Hornady's 40gr V-max at around 2200fps
If you need a larger caliber, go with a 38 special and use a max load with a double ended wad-cutter in a rifle.
BTW, The grease will not stay in the nose and would just make a mess.
Paul