baldhunter,
Sorry, but you don't understand what happened with 7mm Remington Magnum pressures and velocities. The change happened a LONG time before the 7mm STW appeared.
When the 7mm Remington was introduced in 1962, the SAAMI industry standards were copper-crusher pressures (then called PSI--pounds per square inch) even though they were worked up with copper-crusher testing, and 26" barrels. As electronic testing started to be used, it was not only determined that copper-crusher numbers were NOT PSI, but the 7mm RM often resulted in wide variations in pressures (both up and down) with certain powder/bullet combinations.
As a result, the SAAMI pressure standards were reduced to accommodate the variations. At the same time, the standard test barrel length for bolt-action cartridges became 24", not 26". BOTH reasons are why the advertised velocities of 7mm RM muzzle velocities were reduced considerably. It had nothing to do with the 7mm STW, which was introduced a long time after those changes.
The 7mm STW's factory ballistics have never been reduced, because they were developed AFTER the change to electronic testting. But you may be remembering when the 7mm was a wildcat, and many people (Including Layne Simpson) were reporting muzzle velocities close to 3700 fps with 140's and 3500 with 160's. But when Remington pressure-tested those loads, they were way over the long-time SAAMI maximum of 65,000 PSI for ANY cartridge. In fact most were 70,000-75,000 PSI. Whether that is a safe pressure level is another question--but SAAMi prefers to stay on the safe side, so the factory-standard velocities were reduced.
I have no idea where you got the idea that 7mm STW factory velocities were reduced because of the 7mm RUM. I checked the record of 7mm STW factory velocities and found they're basically the same as when the round was introduced, though they can be a little lower due to some bullets resulting in higher pressures than others--and some newer bullets do.
