These rounds are not exactly cheap to manufacture a box of 25 will retail around $45-$50 mark in the 45 and 50 caliber sizes so guys are not gonna be doing a lot of shooting / plinking with these rounds. I have shot a bunch through several different air rifles and have not seen any effect on the rifling. In order for these to fly Out the barrel at fast speeds they have very small, thin rings that barely make contact with the barrel. These are considered bore riders, so there is not a lot of surface to surface contact however, to shoot these accurately, you must clean all the lead or as much as you can out of your barrel before shooting these optimal performance, I can tell you this they are worth their weight in gold In terminal damage/ performance as seen in my Mississippi Airgun deer hunt vide.state governments have been trying for years to ban lead ammo. Some states have succeeded with a ban on use for hunting on public lands. Most states are still fighting it but eventually it will be nationwide or close to it at some point In my opinion. Non-lead options will be the future advancement in airgun ammo.