The original X got a bad rap because of fouling and because ofhigher than normalpressures, with both problems walking hand in hand it affected accuracy. Thosewho sufferedthe bad luck made a big enough stink over it that Barnes was forced into a redesign.....a good thing, in my opinion.

The resulting groovesperform two functions, first they reduce the bearing surfacewhich reduces the operating pressure, less metal riding on the bore takes lesspressure to push it. With copper being lighter than lead it takes a longer bullet to achieve the same grain weight as a jacketed lead bullet. Theoriginal X had to be long and resulted in too much bearing surface, thegrooves on the TSX make a dramatic reduction in bearing surface.This brings thingsonto sortathe same playing field as normal jacketed bullets regarding pressure and often you'll find that TSX's can be pushed faster than jacketed with the same level of pressure.

Second, the grooves allow a "space" for copper that is displaced by the riflingto "collect" and "roll up" off the bore's surfaceasthe bulletpassesdown the bore. With normal jacketed bullets this same displaced copper is dragged or galled all the way to the base of the bullet and is depositedon the surface of the bore resulting in fouling. A jacketed bullet has more contact with thebore and thus more heat and friction produced, this is why you get fouling in the first place.Thelarger bearing surface of the jacketed bullets allows enoughheat and friction to make the fouling "stick". If you've ever cut aluminum or brasswith an unlubricatedcarbide toothedchopsaw blade you'll understand how soft metal"galls" and sticks to harder metal. TheTSX'sgrooveslessen the heat and friction with lessbearing surface to begin with, and the space in each grooveallow the galling metal to "roll up" before it gets "hot" enough to stick as bad as it would with jacketed bullets.....an accidental side benifit.

Barnes suggests cleaning out fouling from jacketed bullets before shooting TSX's to reap thier accuracy potential. I've found this to be true and can only think that thejacketed fouling defeats the design of the TSX's grooves by forcing them to ride over fouling that is "bigger" than what the TSX would leave.

My experience withthe TSX is that they leave less fouling than any jacketed bullets I've used........