I usually separated the upper and lower when testing my trigger polish job. Noticed that if I didn't have something in the way, like a folded up rag, the hammer would smack the bolt release hard. Sure enough there was a bulge of pushed up material behind the paddle. D'oh. Snap caps, the only way to dry fire a firearm without causing minor damage.
Thanks guys. Dry firing with snap caps it is!!
Got it about the snap caps. I usually use them in my M&P pistols so I will have some on hand for the 15 TS. I can then decide when I want to use them. Thanks again.