We used to have a bunch of of old propane tanks on the trail. All the rifles pen those. I suspect it was only the hardened balls from 20 bores and maybe my .69, that penned the
handle sections, but pen, they did.
Smaller bore having higher velocity, as Dan notes, will pen more steel. It is easy to get 1,800fps from a .32, or even 2,240fps from a .40. Mine did. All I had to do was use .398" ball, .0225" patch, LHV lube and 75gr. 3F GOEX. 2,240fps. With that load, I shot off a 5/16" steel bolt at about 25yards.
We also have a steel tube/pipe, with what appears to be 3/8" thick sides. There is a large hole front & back in the centre of that tube. It has a diameter of about 12" & situated about 85yards from the firing line. It used to have another steel pipe inside, hanging by a chain so any hit on it, even from a .32, would make it ring inside like a bell. My .69, even with only a
light charge of 82gr. would make it ring for several minutes. Fun target, now with holes from the steady beating it got, with small balls at higher velocity and larger balls, .58's through to
the .69 at lower velocities.
