Which scope is better for my airsoft sniper a 3x32 or 3x40?

Lets look at the numbers. 3X32. The first number is the power 3x will give you 3 times the closeup view. 32 represents how wide you see. 32mm. So a 3X32 will give you the same close up option as the 3X40 but a little less width than the 3X40. If this is what you want then the 3X32 is your choice. It's up to you.