There is more to 22 rifles than meets the eye. I am not an expert. I just got interested in trying to get a regular off the shelf Ruger 10-22 to shoot under 2MOA and did some research. I tested 8 different brands and speeds of ammo to find just one that would give me 5 shots under an inch at 50 yards on a consistent basis.
Here is a simple primer on chambers and what it takes to build an accurate rifle.
http://www.riflebarrels.com/products/chamber_info.htm