Here is what Toby Bridges of High Performance Muzzleloading has to say about the Hornady SST muzzleloader bullets.

Several cool mornings allowed me to shoot without fear of the barrels of my three test rifles heating up too quickly. Every time I went to the range, I shot with one rifle sighted in with 45 grains of IMR-4227 (with the 250-gr. SST), one sighted in with 42 grains of IMR-SR4759 (with 250-gr. SST) and one Model 10ML II sighted in with 44 grains of Accurate Arms XMP5744 (with 300-gr. SST). All proved fully capable of printing this bullet inside of 1 1/2 inches at a hundred yards. Recovered sabots from each of these loads looked good. Occasionally, one of the recovered sabots would be missing one of the sleeves, or petals. But indications are that the sleeve/petal was torn off after leaving the muzzle, with no affect on the accuracy. A number of groups measured right at an inch across (center-to-center), and two were exceptional. One three shot cluster shot with the 250-grain bullet and load of IMR-4227 measures right at 1/2-inch center-to-center, and another shot with the 250-grain SST and load of IMR-SR4759 is right at 1/4-inch center-to-center! Added In Early June... Left, the 250-grain SST spire-point compared to the 250-grain XTP hollow-point. Right, the 300-grain SST spire-point compared to the 300-grain XTP hollow- point. Hornady's new SST bullet has outstanding aerodynamics for improved accuracy, like this 3/4-inch hundred yard group shot with the sleek spire-point bullet and a Savage Model 10ML II. This exceptional 1/4-inch center-to- center three-shot hundred yard group was shot with the 250-grain SST and a 42 grain charge of IMR-SR4759. Not many modern center- fire rifles and factory ammo can produce this kind of accuracy. Toby Bridges, HIGH PERFORMANCE MUZZLELOADING