It definitely is oversize (Over 62" L+W+H) - just not one of those things they hassle anyone about from what I've heard. From the Sitka Nomad Product Page: "The Nomad is considered Oversized Luggage. 42x16x14 Exterior Dimensions."Well I've had that Sitka Nomad all over heck on many flights/different airlines and no one has said a word about it being oversized- it isn't.
What I've been told, but haven't tried, is that golf gear is exempted from the size limitations. So, get yourself a hard-sided golf bag carrier, pack your gear in there, and throw in one golf club. Done and done...
Only time I've ever flown with my bow - I just wrapped the cams with foam insulation, then wrapped it in a lot of clothing and threw it in a duffle.