Originally Posted by
Geezer
That’s all true.
Every attempt to create improvements through pellet design alone (Sabo, Prometheus, Defiant, “NATO” bullet, etc) has either failed utterly, or produced a projectile that varies (most of them) from inferior to nearly as good, but not quite. In all cases, more expensive than lead round heads.
As I said before, all the designs showed a distinct lack of aerodynamic and ballistic knowledge on the part of their designers.
The problem, I think, is that better performance would need not just different projectiles, but different barrels (twist, especially) and probably actions. The large-bore high-power stuff in the US is showing the way. But it would be a bold maker that brought in a new mass market sub-12 gun that only worked well with a proprietary projectile, and badly with conventional pellets. In addition, you might well find that such a thing was over 12 ft-lbs, albeit inaccurate, with lightweight diabolos. Catch 22.
It can be done with current twist rates and pellets weights between 8-10 grains for .177 and 14-16 grains for .22. Back around 1990 we obtained BCs of 0.041 for a 10grain .177 and 0.049 for a 14 grain .22. I fired a couple of them again afew years ago and got similar values. Accuracy was acceptable for experimental home made pellets launched from Gerald Cardew's projector at 30 yards. Solid lead slugs will always be too heavy for sub 12 rifles.