Well there is nothing to be ashamed about. Hunting is a matter of personal choice. That's one reason that when someone tells me that an in line is an unfair advantage over their flintlock, I wonder why it should bother them if they feel that way. After all they decided the flintlock was a better choice for their hunting needs and desires. The same is true in you case. If you want to hunt with a modern rifle, then by all means use it.

If you need to fill the freezer and want to increase your odds of a successful hunt, then perhaps the center fire rifle is the better choice. If you want more of a challenge in the hunt, still have great odds of scoring, perhaps the muzzle loader would better fill the bill. All you can do is examine you needs and wants and hunt accordingly.

If this is the last weekend and you need the meat, then by all means use the rifle you feel most comfortable with.