Cast hollow points and partitions.

Mark Conner
[subject]
Monday, February 22, 2021, 15:38 (3 days ago)

I had always thought this would be something neat to try, even though expansion can be pretty well controlled with alloy, depth and width of the hp pin and velocity.

Yesterday it was mentioned again so I thought, I have a nice LBT mould I wanted to give this a try with. It casts a hp between 280 and 305 grs. depending on alloy and which pin I use.

This whole process on my part was not very well thought out. I was thinking just drill a hole in the gas check, set it in the drive band of the mould, bring everything back up to temp and cast away. So I drilled a 9/64 hole in the check, got it put in the drive band, some what lined up, reheated it and cast. Easy, looks great too.
[image]Now the part that was not thought out very well... lead will not adhere to the copper gas check very well if at all so there is only 9/64 of an inch of lead holding the halves together. The light is still not coming on in my head until after checking, sizing and lubing I dropped a bullet on the concrete floor, wanting to use it even with the dent in it (I only cast 7 of them) I wiped off the old lube and was going to reapply when the bullet twisted in half.

The light is starting to flicker a bit now. With only the small hole joining the halves together there was no strength to the bullet. When drilling a larger hole I mangled the check trying to hold it.

I think if I was able to get a big enough hole in the check to make the bullet strong enough to take everything that is going to be asked of it, there would not be enough left to act as a partition.

Sometimes ya just have to do it before the light shines.
[image]

Looks like you need a mechanical punch or die too.

WB
[subject]
Monday, February 22, 2021, 16:53 (2 days ago) @ Mark Conner

It's interesting. I like the concept. I wonder if it would hold up in flight?

I have a couple of these, might work

Darryl T.
[subject]
Monday, February 22, 2021, 17:42 (2 days ago) @ Mark Conner

Those punches are sweet!

steve todd
[subject]
Monday, February 22, 2021, 18:14 (2 days ago) @ Darryl T.

You can punch a hole in a nickel if you want to. Would be easy to put holes in gas checks. Maybe 3 smaller holes to keep alignment and keep from twisting in two? Fun project

I seem to recall from my younger years

John W
[subject]
Monday, February 22, 2021, 18:52 (2 days ago) @ Mark Conner

Those modified gas checks were called Wilk Checks. I could be wrong.

In the early 80’s I experimented with this idea

Bob Denning
[subject]
Monday, February 22, 2021, 19:32 (2 days ago) @ Mark Conner

The key is to punch a larger ragged hole (don’t drill a hole) in the gas check. If you drill a hole the GC will spin around the lead center. Try this technique by putting the GC in both driving bands. Bob

Some good ideas Bob,

Mark Conner
[subject]
Monday, February 22, 2021, 21:40 (2 days ago) @ Bob Denning

but I think my itch has been scratched on this one. To me it doesn't seem like a good idea to put something in the middle of my bullet that affects the integrity as much as this did.

By taking more of the center out of the check I see it working more as a copper drive band than a partition. But since none my hp's have ever expanded as deep as the partition I think it is just something I don't need.

Thanks for the good ideas guys but as I said earlier to me I think my answers are in alloy, depth and width of pin and velocity. A fun afternoon anyway, thanks again.

looks like a two part cast bullet aka Lyman cool

Lynn
[subject]
Monday, February 22, 2021, 20:27 (2 days ago) @ Mark Conner

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