What is the difference between a 50 and a 504 bore?
.504 is a more accurate designation of true caliber. Most companies use the 50 designation and then produce barrels that average between .495-.505 caliber. That leaves the buyer to find a bullet that fits his “.50” caliber bore, whatever that might be. With the .504 three number designation, which is ten times more accurate than the common two number designation, you at least know what the land to land diameter is and have a much better chance of quickly picking a bullet that fits. Of course, White bullets are made to fit the 504 bore but many other competing brands fit and shoot well too.
