Been shooting 5.7 since it first came out - Fiocchi Hyperformance Defense 5.7x28mm 35grain Jacketed Frangible Brass Pistol Ammunition

I thought American Eagle was the worst 5.7 ammo. It's slow and dirty. I bought 3 boxes of the 35 frangible and none of it would cycle in either my FN 2 or my Ruger 57. I just sent the remaining rounds ( nearly all) to Fiocchi. It might be a bad lot but for the price of this stuff it shouldn't happen!