It seems rory could have used it many times for getting out of particularly tight spots, so why didn't he use it then?(unless I missed a huge timey wimey spacy wacy thing)
2What episode are you taking about?– user46509Jan 14, 2016 at 15:51
after the pandorica opens, also it never say's that he is human again.– Awbra CadabraJan 14, 2016 at 15:53
1The universe is rebooted after the events of the pandorica. The real human Rory is back and was no longer the centurion. The gun has gone– user46509Jan 14, 2016 at 15:55
1thank you my good sir. You can answer it normally and I will check the box next to it!– Awbra CadabraJan 14, 2016 at 15:57
He did use it:
to kill Amy back in 102 A.D.
in his National Musuem guard disguise: he shot at the Dalek and forced it to retreat!!
(and possibly many times more over the years - or rather centuries - while protecting the Pandorica and Amy within it)
After The Doctor flew the Pandorica into the ever-exploding TARDIS and repaired the cracks / rebooted the universe, Rory was no longer an Auton, just regular flesh and blood again, so he had no Hand-Gun to use anymore.
In addition to @Ixrec's perfect quote: Rory must have been human again, since
immediately afterward Amy and Rory went on their honeymoon which led to River, which would have required them both to be human.
But River is a Time Lady. What does Rory being human have anything to do with it?– ShaneJan 14, 2016 at 18:48
2@Shane A Good Man Goes To War tells us she is human (her Time Lady aspects come from being concieved within the time vortex) Jan 14, 2016 at 19:40
1Yeah it was never explicitly stated, but we can infer it from the wealth of evidence. Most of that evidence comes in the form of River, but when Rory says (in the background) that "I was plastic" as his wedding gets underway (and the fact that, in this moment, remembering being plastic is shocking to him; hardly the response you'd expect if he still were plastic), it seems clear that we're supposed to believe he no longer is. Jan 14, 2016 at 21:59
If you're talking about when Rory was an Auton in The Pandorica Opens and therefore had a gun in his plastic hand, the answer is that he went back to being human after the universe was rebooted in the subsequent episode, The Big Bang.
I was a little confused about this myself until the Doctor said this around the middle of the next season, in A Good Man Goes to War:
DOCTOR: No! No! Impossible! It's all running about, sexy fish vampires and blowing up stuff. And Rory wasn't even there at the beginning. Then he was dead, then he didn't exist, then he was plastic. Then I had to reboot the whole universe. Long story.
Which I'm fairly sure is a confirmation that Rory is human after the "reboot".
Also, in The Curse of the Black Spot, Rory cuts his hand on a sword. An Auton probably wouldn't be damaged so easily.
By the time of The Curse of the Black Spot something else had already happened which would have needed him to be human again.... Jan 14, 2016 at 16:07
@BMWurm I re-skimmed the scripts for the few episodes between The Pandorica Opens and The Curse of the Black Spot, but I haven't found anything else that seems conclusive. Their wedding might've been awkward if he was still plastic but I assume Amy would still marry him in spite of that, and in Day of the Moon he only pretends to get shot. What event are you referring to?– IxrecJan 14, 2016 at 16:13
True, but Eye-Patch Lady is already in Curse which means certain things for Amy (see the third spoiler in my answer below) Jan 14, 2016 at 16:15
Good point. I think I missed all of that because I thought of Amy being pregnant in Amy's Choice but then remembered that episode was before The Pandorica Opens.– IxrecJan 14, 2016 at 16:18
1Unless you can get pregnant by pl.... yeah... let's not go there... Jan 14, 2016 at 16:20