"Bob La Londe" wrote in message
...

"Bob Engelhardt" wrote in message
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On 9/18/2014 4:43 PM, Richard wrote:
...
was capable of around 30 shots it
took nearly 1500 strokes of a hand pump ...

1500 strokes!! Well, OK, that's 50 strokes per shot. Oh, my aching arm.

I wonder what the pressure was.

Lots of modern PCP guns run at pressures upto 3000PSI, but the pneumatic
cannons on the USS Vesuvius only ran at about 1000PSI. It would depend on
the exact design of the gun and the adjustments of the dump valve and dump
valve "hammer". There are guys tuning their PCP rifles today to get
nearly the same velocity out of 1800 to 1300 that out of the box guns are
getting at 3000.

A quick check of references indicates that Girandoni rifle may have only
been pressurized to about 800 PSI. They also claim it had an effective
range of about 150 yards. I think one of those numbers must be off a little
or they had a dump valve mechanism more efficient than most modern PCPs. A
modern large bore PCP can easily meet the claimed specs and even surpass
them, but with a couple hundred years advancement in technology and
operating at much higher pressure.