Modern muzzleloading manufacturers are constantly touting velocities in excess of 2000 fps.  Sure, their muzzleloaders can achieve these velocities with magnum charges.  But, what they fail to mention is how you can achieve accuracy at speeds of up to and beyond 2500 fps.  If you are are satisfied with velocities around 1,600 fps, modern sabots will usually handle the heat and pressure. However, if you prefer to get 2,000 or more fps out of your muzzleloader and still expect accuracy, your sabot alone may not handle the additional heat and pressure produced. But, by simply adding a the Magnum Sub Base, hot high-velocity loads can be handled nicely.

When trying to push any muzzleloader bullet to its maximum accurate and safe velocity it is possible to create more heat and pressure on the sabot than it can stand (this is especially true when shooting your muzzleloader during warmer temperatures). When this happens you will experience sabot failure. When the sabot fails accuracy is non-existent. That's what makes using the new Magnum Sub Base so important. When using magnum loads, these sub bases take the direct pressure off of the bullet's original sabot base and allows them to maintain their shape and perform the way they are intended to perform. See the group achieved with the new Barnes Spit-Fire at a velocity approaching 2300 feet/second, while using these new Magnum Sub Bases.

In the past shooters have gotten creative and even used 28 gage wads to allow them to shoot magnum loads.  Some have even taken to cutting the gas seal off a 28 gage sleeve used for holding the shot when reloading shotgun shells.  There is a much simpler and economical way to do this.  These magnum sub bases have made using the 28 gage wad obsolete.  They perform better than the 28 gage wad and are probably more economical.  Click here to see what Toby Bridges of High Performance Muzzleloading has to say about the use of these Magnum Sub Bases.