I bought four boxes at a gun show at a good price. I don't have a GP100, but I do have two SP101s. The Wolfs are a very stout round in the SP101s. Two cylinders and my hand was actually hurting. My wedding band, on my support hand, was killing the little finger on my right hand. Thats when the fps got my attention. While the SP101 may not have an issue with this round, my hand certainly does.