TPS, Fig 12.16 , p. 515. Jack's gun, assuming 2 5/8" chambers, would have been proofed by Parker using charges that generated an average of 6.1 long tons and 13, 700 pounds and a maximum of 6.7 long tons and 15,000 pounds. Actual and theoretical service limits for ammunition intended for use in the gun are also provided. So if Jack goes down to the local gun shop and buys a flat of Winchester AA Xtra Lights ( 8500psi ) for example, he is 1000 pounds under the average factory load pressures (9500) for which the gun was built.
As another example, say that I want some 16ga shells to go pheasant hunting. I can handload, buy RST's ( which are great shells) or I can get Federal 1 oz Game Shoc loads at my local hardware store. These are 1oz, 2 1/2 dram, 1165fps loads and develop 7, 400psi. From the Fig 12.16 table, I know that my 16ga with 2 9/16" chambers was intended to shoot ammunition that averaged 10,100psi, so they are 2,700psi under the service working limit average. But these Federals are marked 2 3/4" on the box, yet only 2 11/16" when I measure the expended shell. So these shells are 1/8" over the gun chamber length, and precisely as Parker intended for good sealing.
Last edited by Bruce Day; 09-17-2010 at 11:25 AM..
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