Issue in Chrome with Bootstrap 3 columns when using Jquery Isotope (but fine in Safari!)
was having the exact same problem in a project I'm currently working. Only with .col-sm-3, while 2 or 4 would work fine. Weird.
Anyway, what did it for me was simply adding the following CSS as an override on the Bootstrap CSS file:
.col-sm-3 { margin-right: -1px;}
Cheers!