Just to add a bit to what Larry has said that 1,000 lb conversion is a "VERY VERY Broad" estimate & virtually worthless. An old British 3 ton pressure is approximately 9K PSI by a Piezo-Electric transducer. Even using the correct British Ton of 2240 lbs multiplying it by 3 gives 6720 LUPs or an error of over 2200 lbs.
There simply is no consistent conversion between Crusher pressures & Transducer pressures for a wide range of use. When the British first began using transducers, many years before it was standardized incidentally, they did work out a simple conversion that was reasonable close within the narrow range of Shotgun pressures, but applicable to nothing else. It was;
(Crusher Tons x 1.5) - .5 = PSI Tons. Thus 3 x 1.5 =4.5, -.5 = 4 tons PSI. Multiplying by 2240 = 8,960 PSI. Much, Much closer to actual transducer readings than simply adding 1,000.
As slightly different Technics are used, even though similar, I would not suggest this formula for LUP pressures other than the older British Tons pressures.
Back when I first became interested in firearms of various types in the late 1950's all pressure was given in PSI in the US. Mostly this pressure was recorded by the crusher method. It was a decade or so later that LUP & CUP began appearing in the loading manuals along with "True" (PE) PSI pressures. Many manuals began showing Both. In some cases the two readings would be fairly close together while in others they would be wide apart. In all cases however the PE readings were higher than the crusher readings. There is though no simple figure you can add to the crusher pressure & feel you are even remotely close to actual
PE, PSI.
