That combo would work well for deer. Most folks I know who use the 45-70 for deer use the 300 grain. I like the 400 grain mainly because it shoots so well in my gun. My Marlin won't feed some of the 400 grain bullets as they are to long and hang up when they start to lift up to the chamber. 405 with real flat noses do ok. Federal loads a pretty hot load in thier cheaper line with 300 grain Hollow points.