Virtually any ammo in Argentina is also available in Uruguay as that's often where the outfitters are sourcing much of their ammo. The kicker is that most of them make large quantity buys whenever possible to get better prices and may be reluctant to go buy a small quantity of something special. I recall a situation several years ago where an individual in our party wished to shoot 28ga. because of some shoulder issues he was having. The outfitter made the accommodation, but the ammo supplied was 15gram garden gun stuff w/small shot & not any good for pass shooting the high flyers in the winter winds.
I'd suggest that you tell the outfitter exactly what brand and loads you have successfully used in Argentina; odds are good that he can get it, if he is willing. Also, let him know that an extra dollar or two/box will not be a deal breaker, if it is necessary.
Kind regards, tw
