Im ordering the Joe Rocket Blaster 3.0 Leather jacket today or tommorow, depending on how quickly people respond

I'm 19 years old, 6'0 160lbs with an athletic build. I just measured my chest with a tape measurer and got around 39 inches, but I tried on a jacket today and seemed to fit tightly into a 44. The sizes on the Blaster3.0 range from 42-50, and I don't know what to get!!!! People suggest with this jacket ordering a size up...
Any similar body types here? Lead me in the right direction please!!

 

Don't order it yet. Go to your local JR dealer and try some jackets on to see what fits. Then you'll know what size to get if you order online.

 

I went and tried on some jackets..
The 44 seemed to fit me--very snug, but when I was leaning over (like I would on a bike) it loosened up and felt good. Then, I got home and measured my chest to make sure...and I'm at a 39!
I might end up just going with a 44

 

I'm 5'11" and 165. So, very close to your size. I have the Joe Rocket Blaster 2. I wear a medium. It fits me perfectly. I'm guessing it's a 44. It does not show a size other than medium.