The PowerBelt functional concept is OK. However, many people tend to shoot very light ones with heavy powder charges. This gives a high MV and a relkatively flat trajectory. But many who do so fail to realize that big, fat,light, high MV bullets shed velocity very fast, and consequently have less power on impact than a slower, heavier bullet would have had. Then they get disturbed at the lack of performance. Just keep in mind that black powder arms gain power by using massive-for-caliber bullets at moderate to slow velocities.