Mikey, Unless you have the eyes of a hawk shooting silhouettes without a scope wouldn't be much fun for you. A 100 meter shot, off-hand at a roughly 6 inch target (Rams) is a stretch for anyones ability.
Not to discourage you from trying but most everyone will be using scopes with adjustable elevation knobs of a least 18 to 24 power.
The combination of the distances 40, 60, 77, and 100 meters and the size of the targets at each distance, chickens 2x3, pigs 3x4, turkeys 3x5 and rams 5x6 inches make this a tough sport, but a lot of fun.
You'll at least need a good reliable 22 with some consistant ammo to have some success.
If you don't have good combination right now I have three loner rifles that I bring to my matches (Square Deal Sportsmen) all with good target scopes that I use to introduce people to the sport.
Any good 22 that works for you is fine to get started.