Tejano,
Nosler does acknowledge the difference in pressure with E-Tips. In their original data, they advised using the "middle" load as maximum, but in their latest manual emphasize always starting with the "starting" load, because so many handloaders don't.
Also, cupro-nickel is NOT gilding metal. Cupro-nickel is about 75% copper and 25% nickel, and was used for bullet jackets a century ago. It fouled like crazy, and was extremely difficult to remove. The British eventually found that filling a barrel with an ammonia solution, then letting it soak, would get it out--which Townsend Whelen started using, and reporting in America. But I don't know of any bullet company that has used cupro-nickel for bullet jackets for a long, long time.
Gilding metal is mild brass, generally either 95% copper and 5% tin, or 90-10.
Pressure, of course, also varies with seating depth. I have used E-Tips with Nosler's maximum loads for that bullet weight with no problem, when seating them farther from the lands.
