1874 - Yes I believe the average guy could harvest a deer with just what you bought. However I do believe that you may have just got lucky with that combo. You and I and a lot of the other guys in here know how MLs vary even those of the same make and model with their load preference.
Now granted, inlines are a bit more forgiving than traditional rifles. Some of these can be bears to figure out. But to me that is the fun of shooting them.
Thank goodness I've learned to keep a load log for each of my sidelocks or I'd be one confused (even more so than usual) guy.