Military Sweaters are difficult to fit because they are tight fitting. Military Sweaters come in wool or acrylic and currently in several styles.
Length of most sweaters will fit some one between 5' 6" and 6'. Having said that if you are on either end of the spectrum you may be able to get by with the length ok.
Now to blow that all to hell our experience is that for many people say from 40 and up you want to go one size up. The reason why is that sweaters and other military garments like pea coats are sized small is because the population that they are tailored to is young and fit and looking for a slim fit. I know for myself by the numbers I would be considered a medium but I do not like a tight fit so I go with a large.
Vermont's Barre Army Navy Store is a full-service online shop offering camping, hiking, outdoor, military, and surplus gear and supplies.