Hi-Viz, the sight manufacturer and maker of X-Coil pads claims theirs is 30% better than the next best, the Pachmayr, and 60% better than Simms. I'm NOT saying they are right, just what their pad packaging and sales reps say. I have handled their pads and the seem great subjectively. I'm going to put one on my .458 and another on a .308 Saiga, the latter only because the factory pad has somewhat of a "bounce" to it that gets me too close to the eyepiece of the scope. Don