Shooting wild pigeon in Brazil

60 years hunting but new on air rifle hunting.
Just arrived my Hatsan .22 AT44 short ..never even fired a shot with it.
Please advise:
quarry : wild pigeon size of a domestic pigeon
max distance: 40 yds
Please recomend pellet weight to have them very dead at this distance, I don’t mind overkilling I just hate cripple birds.
I dont think I am good enough for head shots ..
Thanks
Fabio. /. Brazil
 
Yeah that's a decent choice for .22 should have plenty of power, I'd say anything in the 15-18gr range should do the job. (Grains not grams)

A few years ago I lived in Sao Paulo for 6 months and loved it, eu posso falar um pouco de Portugues. You have a beautiful country Fabio.

Can you get the "Rifle" brand of pellets there? I saw something about a brand of pellets called that from Brazil, I imagine importing JSB's are VERY expensive like imported electronics and things are there.