hi buddy
well there will be some mix opinion on this question
he short answer is that its kinda complicated. In general .22 caliber guns shoot a larger, heavier pellet at a lower velocity producing a more pronounced trajectory and a larger exit hole .
In general .177 caliber guns shoot a smaller, lighter pellet at a higher velocity producing a flatter trajectory (which aids accurate shot placement for most people) and a smaller exit hole.
There's a lot more, and I do mean a lot more, to picking the right caliber than that, , both calibers would work fine., if I had to make a