Terrible experience with the Barnes 300 RUM . Had about 6 miss fires out of 1 box. Possibly primer issues. The Scricco flew great out my Remington 700 but just like you, cannot find ammo for it.
If you can find it, swift makes ammo equivalent to the power level 3 ammo including the 180gr scricco tip. I purchased plenty power level 3 ammo to last me a lifetime especially when my sendero loved that ammo.