A friend of mine bought the rifle and pistol hollow pointers from Forster and then never used them cause they wouldnt fit his trimmer. It was to short. He gave them to me. I'm not about to turn down something for free, so I took them.
I have an RCBS trimmer and the pilots have a smaller shaft diameter. I put the actual bit in the drill and spun it while holding a file on the shaft to mill it down and fit in my trimmer. It sounds complicated, but its very easy, and cheaper than buying a new Forster trimmer.
As for the actual HP process, its really not bad. Especially if you dont have a HP mold but want some HP bullets. Plus you can make ANY bullet a HP. Just a drop of oil on the drill bit will make it drill WW alloy like butter.
Anyway. I've played around some with it and am very happy. My 95gr RCBS SP in 243 shoot 3/4" at 100yds and with the 1/16" hollow point, it makes a
very wicked varmint bullet with WW alloy.
Very noticeable difference over the solid nose.
I recently used the 1/8" on my Lyman 9mm cone nose bullets. I thought that with the pointyness of the nose it would collapse on itself and make a flatter bullet. When I tested them from my 380 at 20' in water jugs I was surprised. It didnt collapse at all. It wouldve been an almost perfect mushroom with a touch more speed. According to the book they should be going around 750fps. I sized the bullet .356 and after stopping halfway into the 5th jug, the nose measured .390 from a .165 meplat.
Tho I didnt chrono them yet, I am going to try some faster loads and see what happens.
I had actually thought the bullet lost a couple grains of lead when I first shot it, but found out it retained 100% weight. These bullets were 50/50/2% alloy with a plain base gas check.
I can see where a tapered hollow would expand faster or more violently, but I'm VERY happy with the results I've been getting. I'm going to use the 1/16" HP on my 180gr RCBS SP from my 30-06 this year for deer. I drilled them 1/4" deep in 50/50/2% alloy and I think theyre going to work good. I've also been told that a bit of soft wax in the hole makes it work even better.
Below is a picture that I put on another post a couple weeks ago on castboolits.
The first one is untouched, then a loaded and HP bullet, then the results from a 380 at around 700-750fps.