Hollow point struggles

[Barry54]

Hollow point questions

So I finally tried out my NOE 232 grain brass four cavity mold. It looks much nicer than it works for me. I had one cavity that constantly stuck. Smoke from a bic lighter only helped for one or two pours. I even tried rubbing in some powdered graphite with a q-tip and that didn’t do anything either. Moving forward I intend to put a flat point pin in that cavity to see if it helps. But I don’t want to use up tin-rich alloy casting flat points (or cup points).

So I got a quick coat of LLA on the survivors of the first casting session and ran 20 through the new .451” Lee sizer. Success! No more hard chambering and hitting the back of the slide to go into battery!!

So now the next disappointment is I didn’t recover any in my water jugs. I set up a DEF container behind a washer fluid jug and they blew right out the back from my 4” barrel. So I tried the 5” barrel and it blew on through as well. I was at starting load levels of N310 powder. 3.7 grains to be exact. Guessing low to mid 700s for velocity. Why cast troublesome HPs if they don’t expand? Moving forward I intend to try 3N38 powder with a near maximum charge on my next water vessels. Book velocity for max is 997 FPS and over 500 foot pounds of energy!

Now for what was in the pot. It was probably 1/2 full of whatever was casting well last time. Some unknown blend of wheelweights and my other purchased ingots. I was told that they were bullet cores from a military range. I filled up the 20 pound furnace with the backstop ingots and added probably 1/4 roll of solder for tin.

I’ve always dropped my cast boolets in a 5 gallon bucket of water because it was the easiest way to land them without damage. Never tried any other method.

I’ve paid retail price for two 5 lb ingots of pure lead and have most of a bar of pure tin. I was thinking I might need to attempt a 40:1 or 30:1 alloy to get expansion. Not sure how rich it needs to go with tin for good fill-out.

I was hoping the backstop blend would have shown expansion because I have a ton of it. I smashed some of the rejects with my pocket pliers and they weren’t brittle but harder than I had hoped for.

I ended up the day casting with two other new molds. I got about forty five 7/8 ounce slugs before the screw came out of the core pin. It may be stripped. Haven’t looked at it very close. Stuck it and the attached slug in the freezer.

The real joy of the day turned out to be the Lee 500 grain two cavity .458” mold! They fell out when I opened the mold and I finished the pot with it, and called it quits.

[Land Owner]

1.) IDK how to advise you on mold release. In the short term, you can avoid the cavity that sticks. Inelegantly, just don't fill it.

2.) Purchase a set of Drafting Pencils. Using pencils of known hardness is a cheap and efficient way to determine the hardness of your alloy. Here's a link on the Lead and Lead Alloys forum:
https://castboolits.gunloads.com/sho...s-with-pencils

3.) If you have not, read Fryxell's "Ingot to Target" specifically in reference to page 35, HP's:
https://castboolits.gunloads.com/sho...or-Handgunners

[justindad]

I have had large burrs in brass and aluminum molds from NOE that could not be worked out by simply breaking in the mold. Look at the corners formed by lube grooves, vent lines, and other intersections - that is where the most challenging ones are at. Rub the burrs with a strip of leather and see if that helps.

[475AR]

If this was your first casting then I would suggest several more heat cycles to help break in the mold. Several of my brass molds required 3-4 hot casting sessions before they started working well.
Also was the sticking due to the cavity or the hp pin? Some of my MP hp molds I have to heat the pins more so the bullet releases cleanly.

[GhostHawk]

Liquid Wrench Dry Lubricant. A couple of drops on a q-tip and work the sticky cavity over both sides. Also the top of the sprue plate and the sprue plate holes. Then warm the mold with it open and let it dry. When it is up to temp try casting with it.

On my Lee 6 cavity aluminum molds bullets rain.

[Forrest r]

You might consider letting your backstop blend cast hp's air cool when casting. Most of my casting and shooting needs are done with range lead/backstop blend. It's a pretty consistent 8/9bhn when air cooled but can be anywhere from 10bhn to 13 bhn when water dropped.

[IMG][/IMG]

All 4 of those bullets pictured above were cast from my 8/9bhn range scrap.
Top left: Is a hollow based swc that I put a hp in with a forester hp tool. It was cast and air cooled. A closeup of the same recovered bullet.
[IMG][/IMG]
Top right: Is a 220gr bhwc turned backwards to make a huge hp. That bullet was water dropped and as you can see it shattered instead of expanding. The same bullet when cast/air cooled.
[IMG][/IMG]
Bottom left: A 200gr thompson style swc that was cast & air cooled.
Bottom right: another hb bullet that I put a hp in using a forester hp tool. It was cast and water dropped and didn't even come close to expanding.

[cwlongshot]

With one single cavity giving problems. I will tell
You its a problem unique to that cavity. Its NOT seasoning.

Get a good light and magnufyer and some pulled Q tips and start inspections!! You will see whats going in. I suspect a imperfection ie a burr.
Also check the HP assembly. It should slide smoothly without resistance. NOE HP design is quite problematic.

Good luck

CW

[Misery-Whip]

Some may cringe here, but to any new mold especially lee, ill take 1000grit sandpaper on a small block and hit the top surface under the sprue plate, the bottom f the sprue plate and the mating halves of the blocks. Im talking 10 careful strokes on all surfaces. I do dissassemble the mold, but leave the pins in. Then after degreasing ill hit it with kroil, a liquid wrench in an orange spray can and wipe it off. I cast with the mold until the wrinkles stop, and usually all is good there after. Ive never seen a burr in a cavity, not sayin it cant happen. But lees always have them on the mating surfaces.

[Mk42gunner]

I’ve always dropped my cast boolets in a 5 gallon bucket of water because it was the easiest way to land them without damage. Never tried any other method.

This is probably your problem. You are basically making the bullets too hard to expand.

Try dropping them on an old pair of jeans that will be relegated to no longer wearable. Most resources say use a towel, but I had an old pair of blue jeans and all my towles were too good to waste when I started. Basically any non meltable cloth will work.

Robert

[jimb16]

If there are tiny burrs on the edges of the mold, try rubbing the edges with a small hard wood dowel. That usually works for me. It id less aggressive than anything else that I know of.

[megasupermagnum]

I have that exact same mold and shoot it in 45 acp. If you would like, I can send you a handful cast of 20:1 alloy to try. Based on the pretty crazy expansion I saw at 900 fps, I think they would perform well at a lower velocity.

[Barry54]

1.) IDK how to advise you on mold release. In the short term, you can avoid the cavity that sticks. Inelegantly, just don't fill it.

2.) Purchase a set of Drafting Pencils. Using pencils of known hardness is a cheap and efficient way to determine the hardness of your alloy. Here's a link on the Lead and Lead Alloys forum:
https://castboolits.gunloads.com/sho...s-with-pencils

3.) If you have not, read Fryxell's "Ingot to Target" specifically in reference to page 35, HP's:
https://castboolits.gunloads.com/sho...or-Handgunners

Thanks for the link about the drafting pencils! Great idea. I read about a dozen pages in that thread and think I understand the technique.

Yes I read that last month when the topic was what happened to the lasc site. Page 35 age hardening was something I hadn’t committed to memory. I was more concerned about water quenching. I need to learn a new method. 20:1 is preferred!

[Barry54]

If this was your first casting then I would suggest several more heat cycles to help break in the mold. Several of my brass molds required 3-4 hot casting sessions before they started working well.
Also was the sticking due to the cavity or the hp pin? Some of my MP hp molds I have to heat the pins more so the bullet releases cleanly.

The sticking was particularly bad on the right side of the third cavity. I’ll put it under my illuminated magnifying glass and check for burrs before I attempt to use it again. I did heat the mold three times in the oven like the included instructions said but then I got to thinking that might have been strictly for aluminum molds. It will get hotter casting than I got it in the oven.

[Barry54]

I have that exact same mold and shoot it in 45 acp. If you would like, I can send you a handful cast of 20:1 alloy to try. Based on the pretty crazy expansion I saw at 900 fps, I think they would perform well at a lower velocity.

Thank you. That’s a very generous offer! I’ll have to figure out private messages on this site now. I’ve got a zip-loc bag of 40 S&W brass I was planning to put up on the pay it forward page, but if you want first shot at them, they’re yours. Deprimed and wet tumbled.

[475AR]

The sticking was particularly bad on the right side of the third cavity. I’ll put it under my illuminated magnifying glass and check for burrs before I attempt to use it again. I did heat the mold three times in the oven like the included instructions said but then I got to thinking that might have been strictly for aluminum molds. It will get hotter casting than I got it in the oven.

I don't do the oven thing, I use a hot plate and cast 750-800* depending on the mold (more cavities more heat) and I cast 300-400 bullets per session and if they are consistent I will process them and shoot them. If they are not consistent they go back in the pot and re-cast. I did have 1 brass 41 cal mold that I had to do this process 6X, but it finally started casting great and very consistent.

[44Blam]

Sometimes hollow point molds are hard. I find it is best to smoke the cavities and points and then cast hot and keep everything hot.
So, my casting flow for keeping things hot is:
Pour, clean up bad boolits and sprue from last cast, break sprue and drop boolits. Immediately repeat without looking at what you just dropped. This way the mold stays hot with hot metal in it while you deal with culls/sprues...
This also kind of speeds things up a little.

With non-point molds, I generally cast, break sprue, drop boolits, inspect / reject, drop sprue back in and repeat.

[Winger Ed.]

For speeds close to or under 1,000 fps I've had good luck with more or less pure Lead, and just enough Tin or wheel weights
to get a good fill out while running the mold/pot on the hot side.
When I get a little bit of frosting, I slow down or lower the pot temp until it stops.

Lead is cheap compared to the other 'goodies' like Tin or ingots of a specific alloy.
Also, the softer the alloy, the better your hollow points will expand.

For mold burs that you can feel, but not exactly see- I rub the mold on my leg while wearing old blue jeans.
It might take a few times, but it's hard to ruin a mold doing it compared to more 'aggressive' methods.

[Land Owner]

From a thread on the Lead Forum here:

Investigate the ratio:
1:10 = 10% Tin
1:16 = 6.25% "
1:20 = 5% "
1:40 = 2.5% "
1:50 = 2% "

Consider the cost of alloy @ $10.00 per pound of Tin and @ $1.00 per pound of Lead
1:10 = (1# x $10.00) + (9# x $1.00) = $19.00 for 10 pounds of alloy = $1.90 per pound
1:16 = (1# x $10.00) + (15# x $1.00) = $25.00 for 16 pounds = $1.56 per pound
1:20 = $29.00 for 20#'s = $1.45 per pound
1:30 = $1.30 per pound
1:40 = $1.23 per pound
1:50 = $1.18 per pound

Fryxell states (pg. 35), HP alloy at 1:20 tin to lead ratio. Later in the book he suggests HP alloy with at least 2% tin (pgs. 126 through 131) and as Winger Ed and I suggest.

Consider, at these inflated times, how often you will pull the trigger with 1:20 alloy ($1.45/lb) vs. 1:50 alloy ($1.18/lb)! We all need that $0.27 cost differential to buy three (3) primers, or so it would seem.

[JonB_in_Glencoe]

Hollow point questions

SNIP>>>

Now for what was in the pot. It was probably 1/2 full of whatever was casting well last time. Some unknown blend of wheelweights and my other purchased ingots. I was told that they were bullet cores from a military range. I filled up the 20 pound furnace with the backstop ingots and added probably 1/4 roll of solder for tin.

I’ve always dropped my cast boolets in a 5 gallon bucket of water because it was the easiest way to land them without damage. Never tried any other method.

You should try casting with your straight range scrap, and air cool.
BUT, If you don't like the air drop technique for whatever reason, you could try annealing your waterdropped boolits that were cast from your straight range scrap. I bet they will be soft enough.

[JonB_in_Glencoe]

The sticking was particularly bad on the right side of the third cavity. I’ll put it under my illuminated magnifying glass and check for burrs before I attempt to use it again. I did heat the mold three times in the oven like the included instructions said but then I got to thinking that might have been strictly for aluminum molds. It will get hotter casting than I got it in the oven.

I have found that new NOE HP molds need the pins "polished", then heat cycled a few times with the mold, to develop a patina/oxidation...Oven 400º for a half hour, then allow to cool at room temp...repeat a few times.