The shots were at 175, 240, and 270 feet[1]. It had a 4x scope[2].
[1] https://www.history-matters.com/archive/jfk/wc/wcvols/wh17/h...
[2] https://web.archive.org/web/20110724214814/http://www.aarcli...
[1] https://www.history-matters.com/archive/jfk/wc/wcvols/wh17/h...
[2] https://web.archive.org/web/20110724214814/http://www.aarcli...
All sub-100 meter shots, easily achievable with a scoped rifle with 4x magnification and a bit of practice.