4451 as an alternative to 4064 in .308

[jb1023]

So I am looking for an alternative to 4064 as I just don't want to be locked onto one single powder should there be another shortage. I was reading about the 4166 but then saw somebody on another forum mention 4451 was giving him smaller groups with the same speed out of his 308 over the 4166. He did not mention anything about his gun and I'm not a member on that site, nor do I want to be, so I can't query him. Just curious, has anybody used this powder on a short barreled, 20", 308? It does not come up as an option on the Hodgon Reloading Center site. The other reason I am looking at 4451 over the 4166 is that I am gearing up to build a 6.5x55 and the 4451 was mentioned as a good choice for that caliber. Having 2 different powders that could possibly work in both guns just seems like a good thing.

Edit: I should mention that I am shooting the 178 A-Max.