Conventional wisdom is that shorter actions are more rigid than long, and the Axis is a very long action for a .223 Remington. I don't know if a long, closed-top receiver like an Axis is more or less rigid than, for example, an open-top mini action, but it would be less rigid than a similarly closed-top short or mini action. That said, we may be talking about shaving a few hundredths of an inch of group size by going with a more rigid receiver.