Attachment.php Display Error

Using attachment.php I want to have images display 100% their size in my template without being linked but I can only accomplish the following (Note: no other code is included besides below when I test it):

1. Having images appear 100% full size

linked

to their origin location (which does me no good because you almost always then click the image and get taken to a standard all white page with just the image. Coding,

<?php echo $attachment_link = get_the_attachment_link ($post->ID, true, array()); ?>

2. Having images NOT linked but will only display up to 500 pixels in width! (anything under 500 pixels wide works perfectly fine but anything over maxes out at 500.)

<?php echo wp_get_attachment_image( $post->ID, ‘full’ ); ?>

Can someone please help me either A. use DIV tags or CSS to get the full linked version to simply not appear linked, or B. give some ideas as to WHY displaying images without links maxes out at 500 pixels in width. I would be ever grateful, thank you.