ORIGINAL: Triple Se7en
The copper Powerbelts would chronyhigher since they are not solid lead. Only the downrange Ballet energy wouldsee higher numbers.
I did my chronoes on a new barrel. On the first day of shooting I shot only 295 PB's. The barrel was pretty rough. The next day I decided to shoot both the PB's and 245 ballets. I noticed an enormous increase in velocity by the 3rd ballet. Enough so, that I decided to try a few PB's next to see how they compared to the previous days shooting. They chroned an increase on the order of 45% in muzzle energy.
When I returned from the day's shooting the barrel was still rough with burrs. I evaluated the two and found to my surprise that the energies were higher at the muzzle with the ballets. I expected to find energies higher with the heavier PB's because they exit at lower velocity allowing more time for breech gases to more efficiently accellerate the projectile. But then the opposite was true. I suspect that the PB's offered more resistance in the bore along their bearing surface thus reducing the efficiency of the charge resulting in lower muzzle energies.
Regarding the downrange energy, I would expect the 295 PB's to overtake the 245 Ballets for a couple of reasons. First, the 295's PB's are ballistically superior to the ballets, having a greater BC. Second, the PB's exit at lower velocity thus reducing the air resistance forces.Greater air resistance forces resulting from increased velocity and lower ballistic coefficient act to reduce the velocity of the lighter Ballets at agreater rate than the PBs.
Happy Hunting, Phil