You shouldn't just look at the Sierra manual only, I have been shooting the 222 as long as I can remember. For me and my rifles I have found N130 to be the magic pixie dust for 40gr-50gr bullets, the VihtaVuori manual shows what the Sierra manual shows as maximum as minimum in their manual.........
I use 22.5gr of N130 with 40gr Blitzkings, don't just look at one resource
I haven't. Looked at several other manuals. Sierra is just one I don't have.
As far as VihtaVuori that is as hard for me to get my hands on and hard to give $60 a pound for something that may not be much better than what I have or what is easy for me to obtain locally.