Best pellet to use in any gun, IMO, is one that's going to hit what you're aiming at. To ascertain which pellet that is going to do that on a consistent basis, you need to do a bit of paper punching at your preferred range, and with a range of pellets that you think may suit your gun.
Posting a question like this on the board is like asking how long is a piece of string. If 10 people bother to reply, chances are that you will get 10 different answers.
In the end you need to work out for yourself what suits you and your gun and shooting style. The only way to do that is to get out there and shoot.
To keep the cost down, and to avoid buying tins of pellets that you subsequently find to be useless, you could do a lot worse than start off with a packet of pellpax. These give you 10 pellets from a whole range of makers, together with targets to test them on. It's then a relatively straightforward task to see which gives you the best group (ie best consistency).
Should narrow the choice down a bit. Also, when you are confident that your gun and pellet combo are up to delivering the goods, it leaves you free to concentrate on the more difficult parts of stalking/hunting.
HTH
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