I checked with the distributor Huntstuff who said it was 6700 psi as per Kent.
Karl
If one is going to shoot loads with pressures that low remember to keep them at room temperature. As you know temperature can wreak havoc with the pressure of loads since pressure and temperature is a non-linear function. I've seen wads get stuck in barrels just this past season. The user said he had left the shells in the truck overnight and it went below 0 degrees F. They were very low pressure factory loads.
My practice, not saying you should do it, that if a gun is proofed for a certainly service pressure all other things being equal one can just shoot loads within that pressure.
I avoid going over or lots lower, especially in temperature extremes.