SaxonPig, as I mentioned the last time we debated the issue, you need to double check your pressure figures because they're incorrect. If you look at page 4 of the following document (which was published by SAAMI themselves and linked directly from their website) you will find that the MAP (maximum average pressure) for all standard pressure .38 Special loadings is 17,000psi and the MAP for all .38 Spl +P loadings is 20,000psi. The 21,500psi you continue to erroneously quote would, in fact, be a +P+ loading.
http://saami.org/specifications_and_information/specifications/Velocity_Pressure_CfPR.pdf
Also, you continue to treat the SAAMI pressure specs as though they're minimum pressures when, in fact, they are maximums. If we take your word that most factory .38 Spl +P ammo is loaded to 18,000psi, then we can conclude that because it is above the 17,000psi maximum for standard pressure but below the 20,000psi max for +P, it is exactly what it's been advertised as. You seem to fail to grasp that the SAAMI +P designation is about pressure and not velocity. Any .38 Special loading with a MAP from 17,001psi to 20,000psi is, by definition, .38 Spl +P while any .38 Spl loading with a MAP from 1psi to 17,000psi is, by definition, standard pressure.
You also seem to erroneously believe that peak pressure and velocity directly correlate, they don't. High velocities are achieved by selecting the powder which will reach and maintain peak pressure at the optimum rate for a given bullet weight and barrel length. For example, a fast-burning powder which reaches its peak pressure quickly would give the higher velocity for a light bullet and/or short barrel. However, a slow-burning powder which maintains its peak pressure longer would give higher velocity for a heavy bullet and/or long barrel.
One needs only look at the velocity and pressure specs listed in a reloading manual to learn that higher velocity can sometimes be achieved at lower peak pressure depending on the bullet and barrel length. One of the ways that boutique ammo makers like Buffalo Bore can achieve surprisingly high velocity while still remaining within SAAMI pressure limits is to blend fast-burning powder, which reaches peak pressure quickly, with slow-burning powder that maintains peak pressure longer within the same cartridge case. It should be mentioned, however, that blending powder requires meticulous quality control and pressure testing equipment to be done safely and thus should not be attempted by the average reloader.
Finally, you keep repeating that SAAMI reduced their pressure limits in 1974. I would very much like to see a pre-1974 SAAMI-published document showing these supposedly higher pressure specifications as I've been unable to find anything more than internet rumor to substantiate such a claim. My suspicion is that SAAMI revised some of their specifications when the change was made from the older CUP measurement to the newer and more accurate PSI measurement.
http://saami.org/specifications_and_information/specifications/Velocity_Pressure_CfPR.pdf
Also, you continue to treat the SAAMI pressure specs as though they're minimum pressures when, in fact, they are maximums. If we take your word that most factory .38 Spl +P ammo is loaded to 18,000psi, then we can conclude that because it is above the 17,000psi maximum for standard pressure but below the 20,000psi max for +P, it is exactly what it's been advertised as. You seem to fail to grasp that the SAAMI +P designation is about pressure and not velocity. Any .38 Special loading with a MAP from 17,001psi to 20,000psi is, by definition, .38 Spl +P while any .38 Spl loading with a MAP from 1psi to 17,000psi is, by definition, standard pressure.
You also seem to erroneously believe that peak pressure and velocity directly correlate, they don't. High velocities are achieved by selecting the powder which will reach and maintain peak pressure at the optimum rate for a given bullet weight and barrel length. For example, a fast-burning powder which reaches its peak pressure quickly would give the higher velocity for a light bullet and/or short barrel. However, a slow-burning powder which maintains its peak pressure longer would give higher velocity for a heavy bullet and/or long barrel.
One needs only look at the velocity and pressure specs listed in a reloading manual to learn that higher velocity can sometimes be achieved at lower peak pressure depending on the bullet and barrel length. One of the ways that boutique ammo makers like Buffalo Bore can achieve surprisingly high velocity while still remaining within SAAMI pressure limits is to blend fast-burning powder, which reaches peak pressure quickly, with slow-burning powder that maintains peak pressure longer within the same cartridge case. It should be mentioned, however, that blending powder requires meticulous quality control and pressure testing equipment to be done safely and thus should not be attempted by the average reloader.
Finally, you keep repeating that SAAMI reduced their pressure limits in 1974. I would very much like to see a pre-1974 SAAMI-published document showing these supposedly higher pressure specifications as I've been unable to find anything more than internet rumor to substantiate such a claim. My suspicion is that SAAMI revised some of their specifications when the change was made from the older CUP measurement to the newer and more accurate PSI measurement.
