I recently purchased a 20-inch rifle length old school ar15 upper, and the drop-in handguards aren't rock solid, but it's not so bad I can't work with them. I noticed the delta ring sits parallel with the receiver when I pull them off. When I install the handguards, the delta ring sits slightly tilted like they aren't seated correctly. I'm having trouble finding anything on Google. Anyway, can someone confirm this is normal?