If you want a bulletproof vest but don’t want to buy one for yourself you’ll need to ask your employer to buy one for you, or make one.
How To Persuade Your Boss To Buy You A Bulletproof Vest
If you are working in a hostile environment where there is a chance that you might be shot at, it makes sense for your employer to provide you with body armor such as a bulletproof vest. Instead of appealing to your boss on moral grounds, appeal on legal grounds. If you’re a US citizen working abroad you may be protected by your state’s “Duty Of Care” law: http://en.wikipedia.org/wiki/Duty_of_care#United_States
How To Make Your Own Bulletproof Vest
Making a bulletproof vest is not advisable. You can buy kevlar fabric and make your own vest but the level of protection provided will be minimal. If making a bulletproof vest is really something you want to do, get the book Spygame: Winning Through Super Technology Spygame is by Scott French and Lee Lapin, and it explains how to make your own bulletproof vest on page 428. It is also full of other interesting topics such as spy gear, weapons, surveillance tools and hacking.