I'm one of those Hornet rifle shooters that have had no issues with my Lil'Gun loads, from 35 to 50gr projectiles, 12 -13gr loads,
all small pistol primers, in various brass headstamps, in 3 different rifles.
I started at around 12grs, so I have no experience with reduced capacity loads.
I've found my loads consistent and potentially as accurate as I would wish to get.
I've also loaded with ADI's AR2205, the equivalent of H4227, and am a bit more wary of that with some pressure signs over 10grs load,
and case head separations.
Potential to overload there, as opposed to the 'fill the case' Lil'Gun, (although none of my loads have been compressed, as I have seen some loads advertised).
I don't know about reduced loads.
The Hornet cast bullet loads that I have tested were with 700x, 4.5grs with a 45gr pill for 'big group' squib loads.
cheers,
SS