We all know that neck sizing only together with other measures like neck reaming contribute to rifle accuracy. The objective of both is to chamber the bullet so that it is both concentric and parallel with the bore. OK, that presupposes that the chamber and bore also meet those criteria which can’t be guaranteed, but there’s no choice but to assume they are, because they will be in a good rifle and to assume otherwise is not to do the job.The principle is that if the case is fire formed to the chamber and not sized after that, and that if the neck is reamed or outside turned with a Marquart or similar tool, concentricity will be achieved. That’s well and good for typical bottle neck cartridges, but what about straight wall cartridges ? In a maximum chamber the cartridge will be a loose fit and anything but concentric, and straight wall cases can’t be neck sized. Or can they ? How else does one get concentricity ? Or isn’t it important ? Is it sufficient to seat the bullet to engage the rifling or almost ? How is fine accuracy achieved with target 22RF rifles, the case being straight walled ?I’m asking for opinion, preferably experienced opinion, because I don’t have much experience of straight walled cartridges and I have the idea of building a rifle in 38 Special for short range use (50m).[Originally posted to SATalkGuns -- Admin]
Accuracy&neck sizing&reaming
Posted by on October 1, 2006