Swamp,
Bullseye was designed and introduced for the .38 special specifically for the wadcutter loads bullseye shooters preferred. Hence the name. In 1913, handgun shooters used wheelguns in competition, and .38specs were extremely popular. In fact, they are still one of the biggest selling revolver cartridges today. You aren't old enough to remember it, but 45ACP shooters only later (35 years later) began to discover that Bullseye worked well for them also. It wasn't until after WWII that large numbers began to have much of any interest in .45's (their accuracy in GI versions was abysmal), and pistolsmiths had had a chance to find out what it took to make 1911's really perform on targets. The folks at Alliant have it right as far as what they said, today it is recognized as a great powder for .45ACP, but you have to keep in mind that Bullseye itself has been around quite a bit longer than Alliant has, and certainly much longer than anyone working today in their marketing department.
"2.7 grs and a 148 wadcutter in the 38 has cut more x-rings than you and I put together will ever see."
I agree 100% with that statement, even though mine likes 3.0. It was THE standard for the .38spec, and there aren't many newer powders that are as good in that application.