Yep! The only factory ammo I buy is Pistol and Shotgun! I couldn't afford to buy the guns and Factory ammo to feed them! Also they don't make factory for these Chamberings. Although .300 Weatherby is the parent case for the ATLAS, a loaded .300 WBY neck diameter is .335"! .001" to large for the Chamber. My loaded rounds are .332". The Chamber has a tapered neck, .335" at the neck/shoulder junction and .334" at the case mouth. Shooting a 210 gr. Berger VLD at 3050 fps using 79.5 gr. of REL25 and Norma Cases. I start w/ unfired Norma .300 WBY, Cheap Large rifle Primer, 14 gr. of Unique Pistol Powder, Fill w/ Cream of Wheat cereal and shake it down to the NK/Shoulder junction, then pack a 1/4 of a sheet of toilet paper to seal the case. Then spray w/ One shot case lube and fire. Out comes ATLAS. Then expand and neck turn. And you are ready.