doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Low Pressure Shells Pressure?

A couple of things here are worthy of Note. I can't say about this test but I do know that Bell stated in some of his tests, they were taken with strain gages which had not been calibrated. This was in some of his tests where he was comparing smokeless reloads with black powder ones. For this purpose that was fine, but if this same method was used one simply cannot say that 5950 is equal to a factory pressure reading of 5950.
Also with a test of this sort one can only guarantee the pressure for that lot of shells. Next batch may not be the same unless the factory warrants them so.

Looks like Armbrust and Bell were within 250 psi on those shells. But then I know the two of them often collaborated in Bell's research. However, agree with Miller that American factory loads can vary in pressure from lot to lot, because they may switch powder. Their focus is keeping velocity relatively constant, and making sure the shells go "boom" (and will operate dirty autoloaders--although maybe not in the case of the low recoil shells). But with the low recoil shells running around 6,000 psi, it's unlikely there'd be enough of a pressure jump--even with a powder change--to put them over, say, 8,000 psi while maintaining the same velocity.

Those disappeared a couple of years ago. Have not seen them anywhere else. I have started using Fiocchi training loads (7/8 oz) and B&P. Both are low pressure (about 5900 but don't rely on my memory here) and readily available at reasonable prices.

Larry;
I fully agree that as long as the same ballistics are kept I seriously doubt the shells mentioned will jump into a dangerous territory even for old guns. Obviously they have to be kept within SAAMI standards but that isn't what we are concerned about here.
The point is thouh I think we need to be careful about listing pressures in absolute PSI which are not measured with PE gages. Crusher pressures, when taken, are now listed a LUP rather than PSI. Perhaps this pressure recorded by strain gage should be listed as 5950 SGP rather than PSI. As mentioned in another recent thread we need to be "Extremely Careful" about generalizing someone into trouble. That 5950 "May" be extremely close to an actual 5950 PSI by a PE gage, but I don't really think we have a guarantee of it.