Thread: Relationship Between Case Capacity and Muzzle Velocity

It does and it doesn't. Whilst bolt thrust is better controlled the limiting factor is still the brass case. In my Swede for example that's just over 55000 psi. The outcome of hot rodding is loose primer pockets after only a few firings. Plus I'm firing mine in an extremely strong action with top notch gas blow handling. Something that is variable, even in modern designs.
AIs perform better basically because the powder capacity (the size of the pressure vessel) is bigger than the standard case they are based on.
So, no free lunch.