As a former, briefly, owner of a Mossberg 9200A1 Jungle Gun, if you are set on an autoloader, I would urge you in the direction of the Remington 11-87 ... or, a Benelli, if you can afford it. (You could pick one up used, to get the price down.) Both would serve you well.
I was swayed by the glossy ads for the Mossberg, as well as a couple positive reviews in the gun comix early after the Jungle Gun's release. Ah, well, live and learn. You don't hear a whole lot about the 9200A1 anymore, or even see the ads. In my opinion, there're good reasons for that...
GGGlock mentioned the loading/bolt closure issue with the Jungle Gun. Very UN-ergonomic; tactical administration of the shotgun is quite difficult normally, let alone under stress.
Additionally, the gun is comparatively heavy -- as if the average defensive shotgun didn't weigh enough already. Mine did not reliably cycle target and field loads (an important, inexpensive ammo option for practice and competition). Only would digest heavy game loads and buck. If you want to customize the gun to better fit your needs, there did not seem to be a lot on the market for it, whereas there is plenty for the 11-87 and Benelli. And did I mention the 9200A1 was expensive? (I paid $525 a year ago.)
The last straw for me with the Jungle Gun was when the shell carrier twisted during routine use in a three-gun tactical match, rendering it inoperable. Shipped it to Mossberg; they courteously repaired it and promptly shipped it back; and I traded it in at the gun shop the next day.
I'm now very happy with my Remington 870HD pump gun. Even more so after having Vang Comp Systems work it over.
Regardless of what you choose, if you need pro work on a defensive shotgun, I can strongly recommend them; check out
www.vangcomp.com
I'm not going to apologize for the long post. Rather, I hope that my own frustrating and expensive experience helps someone else avoid a similar mistake. A mistake in my book, anyway.
Good luck.
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Check chamber,
mib2000