jQuery.ajaxにCacheが残って困ったら設定 ref: http://qiita.com/leedohyung-dba/items/2cfd683c65aeb7c1108d

1_test.json

{
    "head": "test_a"
}

ajax_cache_test.js

var ajaxCacheTest = {
    jsonFiles: {1:'1_test', 
                2:'2_test', 
                3:'3_test',
                4:'none_test'},

    getData: function(fileName) {
        $.ajax({
            type: 'GET', 
            url: 'ajaxTestJsonFiles/'+fileName+".json", 
            dataType: 'json',
            success: (res) => {
                console.log(res.head);
            },
            error: (err) => {
                // error
            }
        });
    }
}

$(function() {
    _.forOwn(ajaxCacheTest.jsonFiles, function(fileName, key) {
        ajaxCacheTest.getData(fileName);
    });
    $("#reload").on('click', function() {
        _.forOwn(ajaxCacheTest.jsonFiles, function(fileName, key) {
            ajaxCacheTest.getData(fileName);
        });
    });
});

meta

<meta http-equiv='cache-control' content='no-cache'>
<meta http-equiv='expires' content='0'>
<meta http-equiv='pragma' content='no-cache'>