From what I understand, velocity is a good proxy for pressure.
If a manual shows X grains give N velocity and you get the same thing, your pressure is the same too. But if you get N+ something velocity, your pressure is greater than they got in the test barrel. There is no free lunch.
Of course, you have to adjust velocities for barrel lengths and in the end brass condition rules. I'd run brass at 75K psi if I could still get 6 loads out of it.
