@pechelman @Chibs I typically wear a Large IH UHF/Jacket. 6ft, 40" chest..
This is the Medium on me:

This is the Large:

Loosely speaking 1.0" or so difference in the P2P at a quick glance. Slightly more option to layer with a jumper/sweat underneath if wanted to on the Large. I would personally go for a Medium with just a tee underneath.
I hope this helps!


