I have the Black and Antique Vests. Have wanted the Gunsmoke but it has been sold out for months in the medium. I am 5’6”, 175 lbs, Chest 42” and medium is plenty loose fit, but believe small is not big enough for chest size. Western shirts also fit the same way nowadays, what use to be a large is now a medium. I also have a Cripple Creek vest, but the material and workmanship from STS Ranchwear is superior to all other brands that I am aware of. It is a heavier vest than the Cripple Creek.