Thread: Speed vs pressure

A question for the gurus...
I have a load developed, and I know it’s muzzle velocity. If I use a different brand of case (or a different primer) with the same powder and projectile, if I’m getting the same speed can I assume that the pressure is the same? I realise that to achieve the same speed the powder charge is likely to be different between the loads.
Another way of looking at it is...does it take the same pressure to push a certain projectile at a certain speed (out of the same barrel using the same powder)?