Lyman 358156HP fillout

[hhilljr]

Hello:

I have been struggling with this mould for some time, and cannot get good, consistent fillout, especially around the hollow point. I first used straight wheel weight lead, and most recently mixed tin with WW at 20-1. I am casting about as quick as I can to keep the mould and pin hot, but I'm lucky if I get one out of ten bullets that don't look like I dug the nose out with a pocket knife.

If anyone else has had these same troubles and overcame them, I would greatly appreciate help.

Thanks in advance.

[johniv]

Sir, I made a bracket that fits over the edge of my pot, that has a hole in the lower lip , into which the hollow point pin is inserted while I am removing the boolit from the mold. This bracket allowes the pin to hang into the lead in the pot and so stays hot . Works for me. I dont cast a lot of hp's so one bracket is all I use it is sort of a "Z" shape with a hole for the pin in the lower arm of the Z.
I hope this is clear.
John

[StrawHat]

Keep the HP spud hot and it might take care of your problems.

John's method is interesting.

The 358156 and the Keith designs were based on 20-1 lead-tin so your alloy is correct.

Could be your spud has a burr on it. Try cleaning the spud by shoeshining it with crocus cloth or other abrasive paper. Not too coarse, something nice and fine.

I use 358439 with the same alloy and don't have that problem. My problems revolved around clogged vent lines.

[Larry Gibson]

hhilljr

You have to cast hot; that means the alloy temp is higher than normal. I normally cast between 650 and 700 degrees but when HP/HB moulds are used I up the temp to 750. I also made a hanger out of wire that keeps the HP pin in the flame (see picture below). Lastly you must get the alloy into the mold fast and leave a big sprue. This may mean unscrewing the bolt stop to let more alloy out of the spout quicker.

Larry Gibson

[HORNET]

You most likely have a venting problem at the pin. Check the vents in the block faces and recut if needed (chasing them with a scribe works well) then set a small square sharpening stone (I use an India stone) in the semi-circular groove for the hollow point pin. Slide it back and forth a couple of times carefully. If you don't have a small stone, you can use a fine file. What you're trying to do is just break the sharp corner where the groove meets the block face. Do both sides. All you want is to just remove that sharp corner. That'll let the air and gasses out so that you can fill that cavity fast before the melt gets too cool to flow into those corner details. Cast hot and fast and they should fill out.

[Bass Ackward]

Larry,

You cheat.

Hi Hill,

Another trick is to mold and as soon as the sprue hardens, rotate the mold upside down so that the heat rises in the bottom of the mold waiting a few seconds for that to happen. It helps to cool the base too if you are running a hotter mix to get fill out.

One last thing that I always did was to cut down the length of the hollow point pin. I never want a hollow point pin going into or under my first drive band. That weakens the drive band by allowing it to collapse under forcing cone transition and engrave of the rifling.

This will produced a bullet capable of higher velocity without having to hardening it. And in the case of the 358156, a little extra bullet weight is another plus not only for the bullet, but the amount of lead weight in the cavity for a higher pressure fill on the nose.

[hhilljr]

Thanks for the excellent tips guys. I'll double check the venting issues first, and then it might be time to fire up the propane torch. Thanks again, everyone.

[Larry Gibson]

Bass

All's fair in love and war and I love a good HP!

Larry Gibson

[cuzinbruce]

I have that same mould and it should cast fine. Mine is not a problem. Bought it used, took it apart and boiled it in washing soda before I used it. Has to be absolutely clean or you will get bad fill. If you don't want to boil it, use lacquer thinner or acetone to clean it. (burning the oil off by casting mostly doesn't work) Might help to smoke it with a butane lighter (NOT a candle!). Then get the lead hot. When the bullets start to frost is when you can back off on the temp a little. Also try a dipper instead of a bottom pour. Then it is slow and steady with the pin, putting it in and taking it out each time. Great for hunting, a bore for target shooting. It is a gas check design and you want to HP to expand if you are hunting so keep the lead soft, 16-1, 20-1 or so. No wheelweights.
Good Luck

[Bret4207]

A trick I picked up from Skeeter Skelton, and if you don't recall Skeeter you need to read more, is to twist the HP pin after the sprue starts to harden.