Reagan was born in 1911...
i don’t think they were hiring in 1973 when he would have been eligible to serve. Between 1070 and 1975, active duty personnel went from ~3mm to ~2mm. http://72.14.209.104/search?q=cache:tVUt4NclzUwJ:www.infoplease.com/ipa/A0004598.html+active+duty+military+personnel+history&hl=en&ct=clnk&cd=3&gl=us&client=firefox-a