I have used them since they came out & would not consider anything else!! My understanding is that they are just softer than the gun barrel ( and I assume this to mean choke tubes also) so as not to damage the barrel ! I shoot them from my old faithful Mossberg 835 in 3 1/3 inch. # 6 shot using a MaddMax choke tube ! They are AWESOME

If you do try them let me know how they work for you & what your gun & choke combo is! "Callem Close And Shoot Straight "