According to
http://www.magnusbroadheads.com/snuffers.htmlthey say that the cutting diameter is
"#10945 170 grains, 1 13/32" diameter". While the picture seems to dwarf your 125g slick trick, I was surprised to see 1 13/32 as the diameter. I guess I'm just used to hearing about the massive diameters of expandables, lol. Still, no doubt that they'll serve you well especially when talking about thicker skinned game. Let us know how it flies.