This is one of the articles I was reading, the other one was in American Rifleman.
Sabots Because of the similar velocities generated by conventional handguns and muzzleloaders, it didn't take long for muzzleloading enthusiasts to realize the dramatic potential of jacketed pistol bullets as muzzleloading projectiles. Jacketed pistol bullets of .44 and .45 caliber when enclosed in .50 or .54 caliber plastic sabots, retain energy almost as well as conicals, do not exhibit nearly the recoil levels of heavy projectiles, and normally produce flatter trajectories.
Sabots are also highly forgiving of bore size and variances between rifle brands or individual rifles of the same brand. A good sabot can help an average rifle shoot tighter groups over longer distances. Sabots are also more flexible for hunting everything from rabbits and varmints, to deer, and even elk sized game. A .44 or .45 caliber pistol bullet, however, cannot deliver the kind of shock effect or wound channels associated with heavy conicals. Still, for most muzzleloading situations a sabot provides good performance.
TIP: When working up sabot loads, don't forget to examine the fired plastic sabot itself. It should be intact and the petals blossomed. If it is unusually distorted you either need to back off on your propellant charge or obtain more substantial sabots that are designed for heavier loads.
Solid performance can be gained from Hornady's XTP (Extreme Terminal Performance) bullet in a wide variety of guns for a number of roles. I have used XTP's in 180-grain configuration for coyotes and long range varminting, 220 and 240 grain for American pronghorn hunting, 260 and 300 grain for whitetail and mule deer. The 300-grain XTP is accurate, possesses superior expansion and penetration characteristics, and is highly versatile in a variety of guns.
When Thompson/Center had to develop a new sabot to stand up under the pressures created by the Magnum muzzleloader loads of 150 grains of propellant it chose the XTP as the bullet for its new Mag Express Sabots. Mag Express Sabots have longer petals and a deeper cup than standard to help meet the increased pressures generated by Magnum loads. The XTP is also marketed in T/C's Break-O-Way sabots. Break-O-Way sabots have a three piece design encompassing two sabot "halves" locked in place by a woven wool "doughnut" pre-lubed with Natural Lube 1000 + Bore Butter, inducing an almost instantaneous separation of the sabot from the bullet for superior accuracy.
Swift Bullet Company is packaging its highly regarded A-frame bullet in new A-Frame Black Powder Sabots for .50 and .54 caliber muzzleloaders. Super Glide sabots are featured in 240 and 300 grain .44 caliber hollow point A-Frame bullets for .50 caliber and 265 and 325 grain hollow points for .54 caliber muzzleloaders. Swift bullets are famous for deep penetration, reliable expansion and superior weight retention.
The Nosler Partition is considered one of the bullets of choice for big game hunting around the world. It features a soft lead core divided into two sections surrounded by a thin fully tapered metal jacket for controlled expansion, superior mushrooming, and weight retention. A 240-grain Nosler Partition provided superior accuracy in recent tests of an Austin & Halleck rifle producing 1 3/4-inch groups at 100 yards from a bench rest.
Several firms market the Barnes X-Bullet. The X-Bullet is an all copper hollow point offering superior penetration and excellent shock/energy transfer at velocities as low as 1000 fps. It is available in 250 and 300 grains for .50 caliber and 275 and 325 grains for .54 caliber rifles. Many hunters believe the Barnes bullet to be a good sabot round for deer, elk, and bear hunting.
Newer rounds to enter the sabot market are the Polycarbonate Tipped bullets such as the Thompson/Center PTX Bullet and the Traditions Silver Lightning. The Polycarbonate tip improves ballistic coefficient and prevents deformation during loading. A tapered jacket with 8 serrations vents bullet deformation for fast expansion on initial contact. The Polycarbonate post continues expansion in the lead core as the bullet drives deeper. The core and jacket are interlocked to prevent separation. This bullet is also recommended for Magnum muzzleloading loads for penetration and controlled expansion at higher velocities.
Muzzleloading with black powder or Pyrodex is a low velocity undertaking because of the relatively low energy generated by these propellants. Muzzleloading enthusiasts should always be wary of ultra-high velocity loads or penetration bullet claims.
A summary of performance expectations for all of these projectiles is that for most large game muzzleloading situations at ranges out to 150 yards, a hunter can expect the best overall bullet expansion performance and energy retention from swaged lead conicals and sabots. Jacketed pistol sabots (240 to 300 grains) will serve for lighter game up to mule deer and elk size at ranges out to 120 yards. Round balls in .50 and .54 caliber are good deer sized game performers out to 70 or 80 yards. For larger game consider .58 caliber or larger round balls out to 70 yards. For potentially dangerous game, go for heavy conicals in weights above 485 grains. Staying within these limits and ranges insures a solidly performing muzzleloading rifle capable of confidently taking any big game animal in the world.
Like anything else I guess I'll have to try them out on my own, and see what works best.