Not just the powder companies. They need to do a better job in reloading manuals, too. I just bought a Savage 99 in 250, which has the 1 in 14" twist. Some manuals use a 1 in 10" test gun and never mention that some loads won't work in the older guns. Nosler just flatly states that none of their .257 bullets will work in a 14" twist - hows that for covering your butt!