There was a bullet made, some time ago, but British, I think, using copper tubes, closed on the top-end, and shoved down into hollow pointed bullets, expressly cast for these tubes. Some tubes were empty, open end up to promote rapid expansion, while others were closed end up to delay expansion, while others yet had detonating compound, usually chlorate of mercury (seems to me)- however might have been the old standby used for pill locks and tube locks. This formula I have read, was outlawed in 1898 as it was somewhat unstable if mixed in a slurry and dried, rather than in powder form.

5 parts Potassium Chlorate
1 part Sulphur
1 part Charcoal (soft or hardwood, not known)

When I tested this formula I did not know about the slurry/dried as being unstable.
I bored a 3/8" hole in .58 calibre solid base bullets for my Hawken. 3 shots would cut off a 12" Aspen tree. They were fun to shoot, but somewhat of a concern when loading.
After finding out the slurry mix I was using was unstable, I ceased in this venture. Initially I was using the compound for my home made percussion caps.
Due to the Chlorates these percussion caps produced fouling that was VERY corrosive.