Fine for deer, Tom. The three grooves will help with the lube. The lube soaked wad will also help.

As far as calibre - that's only a little .50. I used an Italian Percussion Sharps .54 with a tapered (my rendition on the original) 440gr. slug on a muley buck, a bunch of years back, driven by 120gr. 2f. Killed him just fine!