Bruce Buck on the Argentina Gun:
"There is certainly no shortage of 20-gauge autos to pick from. Currently, the most popular in Argentina are the Beretta 391s. They have the reputation of reliably handling a wide variety of ammunition. I won't say they never break, because everything does, but they are very, very good. The 391 also can _ a long time between cleanings, which is a big help when you consider that you can shoot four flats of shells in a couple of hours. I've used 391s in Argentina several times and, other than one loose stock bolt, have never had a moment's trouble. The previous Beretta auto models, such as the 302 and 303 from the 1980s, are equally durable, as is the Browning B-80. This latter gun is mechanically identical to the Beretta 302.
The Benelli M1 Field, Montefeltro and Legacy also are well respected. The short-recoil action kicks more, but in a 20' you won't notice it. What you will notice is that the guns seem to be able to go for months without cleaning, because sooty gas isn't used to operate the action. The good lodges will have someone clean the guns for you each evening, but it never hurts to have a gun that shoots clean. The Benellis are also excellent in rain, just in case you get a rare downpour.
You don't see as many Browning Golds or Remington 1100s, but they are good guns. If you have one of these and enjoy shooting it, by all means bring it. I think that they have less recoil than the Berettas or Benellis. This is particularly noticeable in the 12s, but it's also true of the 20s."
- Bruce Buck is Shooting Sportsman's Gun Review Editor.
Taken from Buck, Bruce. “The Argentina Gun”. Shooting Sportsman, volume VI, November/December 2004. Down East Enterprise, Inc. USA: November, 2004.