Pete, maybe you have posted pictures before, but would you mind posting a pic or two of your process for drilling hollow points?
I re-read above and see I make a lot of positive statements! I look at this as having walked down the road; taken all the 'scenery' in...... and tested what I see!
No camera at the moment; but I have some older pictures and I have a scanner!
So why don't I like cast HP's??? Only my older ones are straight! HP's are hard enough to cast without having misalignment when your done!
Look at this scanned closeup This is a close range .44 defense load. Close range because it can't make a 600 yard Keith shot! This is a Lyman mold 429244 about 35 years old. You can see the HP off several thousandths with the naked eye. A sharp eye will see a lack of fill at the bottom. This is problematic with the pin not being hot enough (hotter than the blocks) I didn't care here as the bullets are close range only. Here, Ian's comments of brass pins is a good one as thermodynamics improve.
I have a lathe mill combo in my garage which has a collet chuck and collets as well. But my little 3" lathe is so handy right in the loading room! Before my newer equipment I had this "crooked cast HP syndrome" So I pondered on it. A drilled HP would solve my problems if it could be done on center (unlike Lyman) and quickly enough to not make casting a big timesaver. I need to modify my little guy for collets I thought. I had a brain storm that worked! A collet has to pinch tighten on the work. I used pipe threads....... tapered ones! even pipe at times! I would chuck up in the 4 jaw chuck and then bore into the threaded end to .001" over sized diameter. Length for specific bullet. i would then remove the chuck from the lathe and using it like a vise of sorts I would soft jaw it in the vise and saw two vertical slots 90° apart. A nut threaded with NPT thread finished the job. I have ratchet box end wrenches so tighten/loosen is quick. The flat bottom gives me a positive repeatable stop for fast accurate drilling. They hold bullet 'dead nuts'. Here's a picture of a couple.... I use a steel alignment pin to indicate into the 4 jaw.
Jacobs chucks.... Never paid a lot of attention to them. But they make them in precision grades. I saw one on sale cheap (because of odd mount) I bought it! The 3/8"-24 female thread was perfect! Now this is an accurate chuck! A chucked
(and sized) bullet will usually run in .001"! But lets talk cast bullets.... It is rare that they cast truly round.... I even consider .0005" to .001" max good. Then, a bullet 'rolled' in a mic will show the mold seam 'proud'. I don't see 'dead nuts' and .001" being different on target. A couple MOA load may take a little more off center but a 1/2 MOA varmint load won't!
I will use the Jacobs chuck always for modifying bullet length... (as I talk about a lot!) Fast and accurate. I have a blind hole and use aluminum pins for a positive stop and have a large assortment of lengths. I HP handgun stuff as well with the chuck using collets for 'benchrest' loads.
I had a couple pictures on file that sort of shows this work.
Pete