The old 200gr lead flat nose factory load killed a bunch of game back in the day. Google shows the original ballistics were around 1200fps for the 200 out of a rifle. I don’t see any reason why you couldn’t duplicate that with a strong revolver like the Vaquero. The same weight bullet at 1000fps would probably be effective and easier to handle too. I guess it’ll boil down to what shoots to the sights. Just make sure whatever bullet design you choose has a good sized flat on the nose.