“I guess I should have asked if the pockets are big enough to conceal a 9mm?”

Absolutely! As soon as I got my jacket I tossed a 4" barreled, 6-shot, 38 special revolver in, just to see if it would fit (S&W model 15 To be exact). To my surprise, not only did it fit but, it was truly concealed....meaning it wasn't even noticeable from the outside.