Home Forums Hunting & Shooting Gunsmithing inconsistent rifling at throat

I see this all the time with factory chambered rifles and by smiths who dial both ends at the same time. The names on that list includes some very reputable smiths and even barrels installed by the makers of the barrels. Holding the barrel at the shank with a collet in a CNC lathe or a 4 jaw even if the end is brought into perfect center it doesn't account for the internal curve in the bore that every barrel has. Done this way some rifling will start right at the neck while on the other side they can start as far as .500" out. This starts the bullet slightly canted into the bore. No amount of lapping or grit covered bullets will help it in any way. Oddly some guns can be quit accurate done this way but since it is not ideal why not avoid it. Ideally you want the rifling to start at the same distance from the neck all the way around. That is only able to be done by only dialing in at the throat and 2" farther in on the end you are working on. It is commonly referred to as the Gordy Gritters method. We dial in this way for chambering, crowning and muzzle threads and gives us consistent accuracy on every barrel job.