quote:

Originally posted by trmungle:
I find it hard to believe that there would be 19 tons of thrust against the locking bolts of a double gun. At 60,000psi the thrust would be about 10-12,000 lbs against the breech face depending on the ID of the cartridge. Tom

Apples and oranges again. No two yardsticks for measuring pressure are the same, whether bolt thrust or chamber pressure. Each is unique. CUP and PSI (piezo) both measure chamber pressure but are not readily convertible. ALL British rifle cartridges were standardized using the Base Copper Unit of Pressure yardstick, which measures the thrust of the case head against the breechface, not the locking bolts. That is the unit of measurement referred to by the "19 tons" mark on the rifle above.

The British standardized on BaseCUP long before the Nitros appeared, and it remained the official standard until Britain became a CIP member in 1980. Kynoch STILL uses it today, although they also measure the CIP mandated chamber pressure, using the piezo method, in the same pressure gun at the same time.
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"Serious rifles have two barrels, everything else just burns gunpowder."