@WildRose made some very spot on points. I will add that copper is 20% less dense than lead. So the physical size diff between copper and lead bullets is a bit more than he described. Stability is a very big component to terminal performance. Marginally stable bullets can work very well ballistically, but have an increase potential for failure on impact due to yaw impeding fluid from entering the hollow point which starts the expansion process. This holds true for any bullet not just copper bullets. The stability calculators are for determining ballistic stability. That means stability in flight and has nothing to do with whether or not a bullet is stable enough for reliable expansion and terminal performance. I think many of the reports of brand xxx (fill in the blank) failed are not actually a bullet failure but a failure to have enough stability to ensure proper terminal performance.
There is a notion or reputation out there that copper bullets need more speed to work properly. I will address this only regarding our Hammer Bullets. Our bullets do not need more speed to work with full deformation. We impact test our bullets down to 1800 fps for proper terminal performance. This doesn't mean a slight deformation. We expect full deformation and shedding of the nose. Less than this we would almost consider a failure. Our bar is set high for terminal performance. I will add that we don't need none or shoulder impacts to see great terminal performance. If you are a shoulder shooter or a pure lung shooter they will work very well.
This is the classic rabbit and turtle race. The rabbit gets a head start and the turtle always wins the race in the end. The question is, at what point down range does the turtle pass the rabbit? Often it is farther down range than the usable hunting range of the rifle combo or the hunters need / ability.
I still find use for round nose and flat point bullets. It is LRH, but setting numbers for anyone but me is foolish.
I've been shooting awhile, and never recall a listed BC that wasn't criticized in the media of the times, as not being real, but inflated.
1) You may not get the BC listed by a manufacturer, but maybe it's an incomplete understanding of how those numbers are derived, rather than over inflation to sell bullets. There has been a lot of work done in this area, and more to be done.
2) You can't disbelieve the manufacturer, then ask for a "real world" number from an internet site, and do any better.
3) You have to validate your own system. This has not changed since I started, and must be technically not ego driven.
4) Whatever feedback you get from testing is what you're going to have to incorporate into your shooting. Like it or not.
A lot of credible long range hunters, and shooters, here that I have learned from, and have helped me tremendously in advancing my meager skills.
I think there are many of us that define "long range" differently for ourselves, and that is reflected in our bullet choices. Meaning more turtles than hares, and that's OK. As is trying to win at longer races.
