The story I got once was that Swift makes a harder copper alloy bullet than others such as Partitions. Whether that is true or not I do not know. That would give some credence to worries about using them in old doubles, but you do not have an old double.

But then one turns around and uses steel jacketed solids, which the rifling cuts into in many cases I suspect through the gilding copper. So how can Swifts be worse than Woodleigh steel-jacketed solids?