I'd recommend a read of https://www.vihtavuori.com/reloading-data/rifle-reloading/?cartridge=13
It shows N140 is possible for light bullets, however it doesn't look much use for your requirement. I've used N160 extensively for the 260 Rem in medium bullet weights with success. I'd suggest that you wait until things ease up and then get some N160 or N555.
Regards
JCS