RGThis can be done but involves a little work
This can be done but involves a little work. How I did this: I hunt ghogs and varmint bullets usually have large meplats and therefore low BCs. I wanted a high BC bullet that came apart after impact. Vmax and other tipped bullets had higher BCs, but I preferred non tipped ones. I would chuck a target bullet with a high BC in a B&D drill mounted upside down in a vise. Spin it slowly as you run a metal file back and forth over the tip until enough is gone to allow insertion of a drill (1/16" usually) and slowly remove jacket material as the bullet spins. Drills with a hexagonal shank could be hand held and appropriate pressure applied. A good bit of material is removed. File the tip to remove burrs, then spin while holding 4-0 steel wool on tip to polish it as well as thinning a bit more. Range testing confirmed high BC retained and terminal ballistics was perfect...common not to have an exit wound. On large game you do not want bullet opening too soon, so a 1/16" meplat might be ideal. Some work but I kill less than 90 ghogs a year, so i made these during winter.
Drilling the lead core is not necessary to get a bullet to come apart, as in a hollowpoint. Drill the lead core off center just a tiny bit will cause that bullet to fly erratically. Thinning the bullet's tip seems more likely to cause the bullet to come apart as opposed to size of meplat. Closed meplats have a lot of jacket material in the bullet's tip and when this is drilled out, the tip is very thin and collapses immediately after penetration. My main hunting is varmints, so the quicker the bullet opens the more likely all it's energy will be expended inside the varmint. Large game needs some degree of penetration before opening. I believe this was why John Nosler developed his bullets.
