06-02-2021, 07:13 PM
(05-12-2021, 02:33 AM)BluntForceTrauma Wrote: Grayfox makes some good points. Come to think of it, there are quite a few magazine-fed weapons in high-power competition, and they all have feed ramps....Yes, but consider this in the AR community the majority of experience is with the 5.56x45 or 7.62x51 Either round is an FMJ class where the ratio of length to neck diameter as well as seating is relatively short. 6mm ARC is way longer and the casing neck is short. The magazine lips are long so the casing has a constraining pivot while the tip is engaging the feed ramp and counter bore.
Also most discussions about the problem deal with a jacketed bullet. I have been working with powder coated cast bullets. The lead will obturate at a mere 7 to 15kpsi, much less than 60kpsi for copper, plus the PC is also deform-able. So any impacts and you have the same concentricity issue you get with a SP tip only worse. As ammunition becomes more scarce it would nice to have a reliable accurate round you can make at home, given primers and casings. This is the reason for my concern with these issues