Yes this is possible. I have changed this for the default post type, but this is also possible for a custom one.
First check the codex:
http://codex.wordpress.org/Plugin_API/Action_Reference/manage_posts_custom_column
function your_columns_head($defaults) {
$new = array();
$tags = $defaults['tags']; // save the tags column
unset($defaults['tags']); // remove it from the columns list
foreach($defaults as $key=>$value) {
if($key=='date') { // when we find the date column
$new['tags'] = $tags; // put the tags column before it
}
$new[$key]=$value;
}
return $new;
}
add_filter('manage_posts_columns', 'your_columns_head');
You can change the $defaults array as you like this way.