.378 gnr ammunition

Hi,

New to the forum, picking up a Reeder custom Ruger no.3 in .378 gnr soon and was wondering if anyone sells loaded ammo?
I'm getting some brass and dies with it but not set up for reloading yet and would like to shoot it asap, don't need hunting rounds just something to try it out.
I've looked and can't seem to find any from boutique reloaders or mainstream companies.
Thanks