Anyone help with ammo identification?

Hello,

I have some copper washed steel cased x54r ammo that has a 147.5 to 148.5gr ( average of pulled projectiles ) projectile..hollow conical base with lead exposed at the concave base...projectile also copper jacketed or copper washed, and no tip color.

Headstamp is 47 48

I checked a few sites with ammo headstamps and couldnt find anything to match.

Was trying to determine manufacturer and date. I had been guessing one was factory and one was date, but not familiar with x54r headstamp numbering schemes,.

Thanks