Initially set your fl die to the point that its actually camming over at the top of the stroke, trim your brass to 1.355, fireform it to your chamber, then use your case gauge to make sure you're setting the shoulder back only .002 or so.
Make sure you arent attempting a "jam" with regard to your OAL..gas guns were never meant to work that way and getting the large diameter of your bullet behind the rib in your magazine can only help feeding.
You guys are making way more brain damage out of this than is required.
knock it off.