We are selling a lot of 50 Texoma Precision Pellets TPP custom air gun pellets 58cal 465gr (.575″). The AEA 58cal provides a unique problem since it has rifling right to the back of the barrel. You need a round that will fit with minimal force, but it needs to expand and form a tight seal on the rifling. I went very old-school to get the design, it was the 1855 Pattern U.S. expanding ball ammo design, that expanded into the rifling upon being fired (Thank You James H. Burton).