NEF/H&R will not advise it...but again it's kinda like one of those "Enter At Own Risk" signs.
Many have done it, and tested it out without harm. I will just say, I haven't heard anyone that got hurt trying a 22Hornet on an SB-1 receiver, not saying it isn't possible as I don't know all the millions of Hornet owners by name eather.
Curiousity killed the cat, but within reason the cat could have been relatively safe. Be aware of pressure signs and the like....One of my SB-1 receivers that i got in trade about a year ago withheld many many rounds of 44Mags from the previous owner and 223's....though there is a indentation/dent from a 44Mag in the receiver(primer area), evidently from a very hot load, or many
Who's to tell, as I got it used
-Aaron