Why you want to wax your barrel is beyond me... If bore butter is not applied exactly proper, you will be wiping rust out of your barrel. There is no need to season a barrel IMO but you do what you want since it is your rifle. I would personally clean the barrel and then protect it with the some quality gun oil.

I will let the bore butter experts tell you how to properly apply it. I tried for twenty years to do it right and never was able to keep the rusty patches from appearing... So now I do not worry about it.

By the way, what kind of rifle are we talking here?