My bullets have flashing....

Or using thicker foil to open the gap a scooch more.

Often wondered about filling a HP cavity with pure.

fiver said:

an initiator tip would help.
moving the foil all the way forward would help too.

Click to expand...

Rumor has it these blow up coming out of the muzzle. Not good for suppressors.

I think drilling a hole through the nose right at the bottom of the foil strip might help. May have to go try that and smack one with a hammer...back in a minute.

Ok, just got back from drilling a 1/8" hole through a couple of bullets and smashing one with a deadblow mallet and one in a vise. Much better expansion this time. The hole collapses and the foil lets the nose halves spread open to make a sort of broadhead shape.

It occurred to me when drilling holes how tough and slick this powder coating is, so I thought some more on that and came up with a couple of things. First, the Polyester coating is so slippery that the bullets just slide on through soft material just about forever, compounding the low-velocity expansion problem. Second, as a jacket, it holds the nose together at the split, making it harder for the nose halves to separate as compared to an un-coated split point. That being the case, a full split point MIGHT be safe to use after all if coated. I'll probably drill some and shoot them tomorrow to see what happens.

Hollow points & foil....should be interesting either way.

So tomorrow couldn't wait. When you have a silencer and a flashlight the test range is always open.

What I did is place a powder-coated, split nose bullet in a vee-block and drill a 1/8" hole through the bullet nose right at the end of the foil at the end closest to the base. That puts it about 1/4" from the front band. That's SIDEWAYS, Freebullet, not through the point in the usual, lengthwise fashion.

This seemed to start expanding in the carpet, and blew a very satisfying hole through the stack of cardboard. Examining each layer closely, it appears that the bullet grew two "wings" as it went through, and after 3-4" the cavity damage in the cardboard pack was starting to grow considerably The exit hole was about .45 caliber but the cardboard was shredded fiber mush radiating nearly an inch all around, indicating what I think is shock energy dump. The bullet did not come apart. I used the long end of a power pole as a backstop and the bullet base is at least three inches inside the pole, with shredded cardboard fragments and shredded wood all around the hole.

So I think this will work, combining the foil strip for an almost-split nose with intact tip, and drilling a hole through the side of the nose right through the parting lines at the back end of the strip. Believe me, it made me a little nervous putting one of these abortions through my silencer, but no harm done this one time anyway, and the hole wasn't perfectly centered. These may not group well if I can't keep the bit from walking.

The Lee mould's alignment pin locations prevent me from cross-drilling the mould for a sideways "hollow point" pin, but I wonder if it wouldn't be possible to drill through the sides of the mould and install slightly tapered half-pins in each side to cast the crush zone in place. Maybe even a crush zone that's more effective than a drilled hole if the tip of the half-pins were filed to a teardrop shape....

you could have an oversized vent line milled in/across the mold and use a series of copper wire pieces to pour a run of bullets.

fiver said:

you could have an oversized vent line milled in/across the mold and use a series of copper wire pieces to pour a run of bullets.

Click to expand...

That's what I was thinking with the cross pin, but the alignment pins are right in the way. The idea was to file a deep groove like a vent line in each mould half, clamp the mould closed, and chase the square hole out with a drill. Then a brass rod could be fitted and wood knob attached so it would poke out the front of the blocks. No stop would be required if the hole wasn't chased all the way through. I kinda like the half-pin idea better. Who knows, it might work ok on its own without the foil, but judging by what the hammer did, the foil split really is what makes it all work.

Sounds like Ian needs a small mill with a good vise and v-block.

I think I can pull it off with a drill press, but will order a new mould first. This one is getting tired anyway after a couple thousand bullets.

Sideways, got it. I miss understood.

My attempts at drilling lead lead me to buy a HP mold. That's a tough task to drill it.

If going through the trouble to mod the mold it would seem alignment pins could be moved.

Those are some encouraging results though. Further testing definitely worth while.

So uhh, what are you naming these? Hollow split heads?

I meant for drilling the existing bullets. A small clamp and v-block with a mill would help. Use a stub length drill to keep it from wandering.

Roger that, Brad. I need to buy a set of jobber drills and some double-ended stub drills anyway, but if I ever get a chance to get into precision machinery I'll likely start with a lathe.

Part of the problem with getting these split points expand is the long, tapered ogive that tends to put a lot of force in the wrong direction. The forces wedge the nose more closed rather than open it up. What little frontal area there is can act on the cross-drilled hole, collapsing it and allowing the split to open up from the bottom, creating a bulge in the middle of the nose and an arrow-shaped tip like this => rather than letting the tip split open like this =<

Ok, weird question. Would a reverse BruceB method work? Use a bit of harder lead in the nose, just to the start of the foil. Might prevent deformation and act like a wedge to initiate expansion?
Think of the possibilities of an HP with a hard lead pointy insert in it. Think of an all lead Ballistic Tip.

Ooooh. Just had another idea. Maybe move the drilled hole slightly forward of where I've been putting it so it's about halfway between the tip of the nose and the front band, and put the foil strip BEHIND the hole, going back through at least the length of the front band and maybe even into the first or second microband. Pressure on the nose would shove it back on impact, collapsing the hole and forcing the foil split open. As the split opened, the nose would pile back into the crack, wedging it open even more. The bullet would likely break up into two or three big pieces with enough mass each to exit a Bambi.

Edit to add I just clicked your last post notification and see you had a similar idea about using the nose as a wedge. By golly this just might work.

Got a photo of a drilled bullet? Just to show us where it was drilled.
Interesting concept. Just need to find the right hole location and where to place the foil weak spot.

I've been meaning to take one of all the ones I've smashed, but have been waiting for better results and hopefully some recovered bullets (if I can get my hands on a three-foot stack of newsprint). Look at the photo in my first post of this thread and study where the foil strips are located (they're all pretty consistent). I was drilling the hole to barely intersect the edge of the foil at the end closest to the base. Off to study the mould and see if I can place strips all the way across the blocks behind the alignment pins, that would be MUCH easier than tweezers and putting short strips between the pins.

While the pot's heating up:



Three on the left on the foil strip show what I'm going to try next, probably with a hole drilled in about 1/8" more toward the nose tip than the drilled one pictured next to them. In the middle are two smashed split/drilled ones, and to the right of the uncoated mashed one (one blow with a hammer squished these 7-ish BHN bullets quite well) are two undrilled ones that I hit with the deadblow hammer. The two on the far right show where I had originally been placing the foil strip.

think about the rod inserted between the cavity's.
not through the sides.
you'd use a 'set' [like 20] of rods then pull the bullets off them after everything cooled.
to heat the mold by running it you'd just have 2 bullets linked together.

Starting to make some progress.

I cast a few with a little bit wider foil strip snuggled up next to the alignment pins so it's just rear of the middle of the bullet length. Two different alloys (50/50 and 3/2 Sticky/Clippy weights) just to see the difference. Drilled holes a little farther up the nose than last time. The "wedge effect" is definitely happening with the strip moved to behind the hole and the hole moved up the nose a little. I bet a couple pieces of #6 magnum shot peened into the hole would really split the bullet open well.

My first attempts are the PC'd ones from the previous picture, showing the slight improvement of adding the hole, and comparing to the latest, un-coated ones with the foil moved back.

Four on the right, left to right: Just starting to crack the body open. Next one is mashed a little more. Next one is 3/2 alloy but the nose folded over so you can see how it behaves when that happens. Last one is 50/50 and mashed pretty far.

I can't wait to see one recovered from your berm or some newsprint. Even from the berm it will give some indication of what it will do.
Moving the foil and hole back does make a difference. Gives a crumple zone for the nose to move into and initiate expansion.