Hi Lead,
One of the most common mistakes made by shooters in all classes is to use to much magnification. Bigger doesn't equate to easier. I have gone the opposite direction and have been shooting on 6x. I don't necessarily recommend that either. I would start on 10 or 12 power and, as your comfort level goes up, raise your magnification. What i tell my students shooting smallbore is that if they don't see the impact of the bullet on the animal and then see the animal fall through the scope, they are using too much scope. Improved hold and follow thru usually allow for effective use of the higher magnifications. but, as with everything else in life, there is a point of diminishing return.
dave