I purchased a core15 in Dec 12. So far it has run like a beast, its dead on accurate, and the price could not be beat. I'm a former member of the US Army 11B, and the guys there make you feel right at home. They setup my optic for me, due to my limited range access. First shot was in the ten-ring. My good friend bought a more expensive weapon from a less knowledgable shop (names left out to protect his pride), and had issues of the bat. When I cracked it open, there was a curl of copper on the left feed ramp due to the huge burrs left in place. I will be a thunderbird customer for life!!! Thanks guys!!