Vafish is correct in my experience. I do know that closing the action hard without the barrel installed absolutely WILL wreck a S&W 3000 shotgun (the Howa-made clone of the Remington 870, sold under S&W's banner in the 1980's). It destroys one of the shell latches (the one you can't get anymore from those who still have parts for the gun). I've never done it, but I got screwed on an internet auction where a like-new 3000 was sold to me at a suspiciously low price. Turns out the latch was bent beyond repair. Oh, well. It made a nice "parts gun" for my two other S&W's, and I got a pristine rifle-sight barrel out of the deal.
Like Vafish said, just go easy and you won't damage anything. No reason to slam things around.
Glock 17, Glock 19, Glock 26, Glock 37
Glock Armorer (AC), Glock Instructor (IW)
Remington 870 Police Magnum, Benelli M1 S90
Smith & Wesson 13-2, 36, 66-3, 681, 3000
Tactical Shotgun Club Member #3000