I'm using masonry.js to achieve the masonry effect on my site. However I'm having difficulty getting the images to stack in the proper places to have a gapless layout. I've made sure all the images are cropped to the right sizes so they will fit perfectly but I'm still getting gaps. Any help would be great! Thank you so much!

Here's a link to the site so far: <http://zechnelson.com/missionsme>