If I travel 152 miles round trip for military duty, can I write off those miles, or does it have to be 100 miles each way or more? The tax form is unclear

Armed Forces reservists traveling more than 100 miles from home.  This means one way not round trip. 

Sorry, it has to be over 100 miles one way.  IRS PUB 3, page 9.

" If you are a member of a reserve component of the Armed Forces and you travel more than 100 miles away from home in connection with your performance of services as a member of the reserves, you can deduct your unreimbursed travel expenses on your tax return. Include all unreimbursed expenses from the time you leave home until the time you return home. See How To Report My Reserve-Related Travel Expenses below for information on how to report these expenses on your tax return.