Peter Capstick had a chapter on him in "Death in Silent Places". Siemel's own book, "Tigerero" might be available on the web.
Siemel hunted in the Matto Grosso area of Brazil. Never realized how huge Jaguars can be until I read Capstick's account.
Didn’t Sasha Siemel ultimately lose one of these encounters?
Didn’t Capstick also tell of his attempt to take a cape buffalo with a spear. IIRC, Capstick got in a killing throw but the backup shooter had to drop the cape buffalo who apparently wasn’t quite ready to die just yet and thought he’d have a little talk with the guy who threw the spear into his ribcage.
Yes.
Mis-remembered Argentina.
The pistol is a S&W .38, as I recall.