Don't ever use Thermold mags. When I got mine in 07 I put a loaded Thermold 30 rounder in it and I could not get it out! Had to remove bottom plate take all internals including ammo out then had to take a 6" pair of needle nosed pliers and gently break the mag apart!
Glad you enjoyed it. Advice to help you continue enjoying this great rifle: don't insert full mags with the bolt locked open. Insert the mag on a closed bolt with a firm push from the bottom to ensure it is fully seated. For best results charge from a closed bolt by pulling the handle all the way back then releasing. Avoid riding the handle forward or charging from a locked open bolt by slapping the handle down; instead pull it fully back and then release. Proper operation prevents the feeding and extracting problems often appearing in this forum.