During a projectile motion lab what factors cant you control that affect the range of the projectile?

Gravity, Wind Resistance (drag), and the movement of the air itself. By movement, I mean a downward breeze can push it down faster, or to another angle which will cause it to deflect downwards. I had this happen to a model rocket once, after going up about 30 feet, the wind knocked it sideways and it came crashing down. However, if you were to do this in a vacuum, you could eliminate all but the gravity part.