Latex in concrete -- Concept applied to Boolits?

[Dannix]

I'm looking at going the +HP option for a 30-30 GB as it sounds like it performs quite nicely as low velocity hunting round in thin-skinned game.

Cast Hollow Points in the .30-30 Levergun (http://www.leverguns.com/articles/fryxell/casthollowpoints.htm)
"Rapid, violent expansion early after impact, followed by a longer narrow wound channel and a small exit." Apparently similar to the Nosler Partition's performance.

I know a member here who just anneals his boolits' noses to make a "soft point" that reportedly expands as readily as an HP. My thought is this approach would allow a greater wound channel as fragmentation is less likely to occur (the above link states the HP petals break off).

That got me thinking though...is there something you could mix in with the lead that would keep the HP petals from tearing off? My first thought was how latex can be used in concrete. Any thoughts? Is a jacket really the only way of holding a HP together?

[leftiye]

Tin toughens the alloy. It can be alloyed up to 10% in lead. Copper does too, but 1 to 2 percent is all that doesn't cause problems with casting. !0% tin and 1% copper yields an 18 BHN boolit.

[Dannix]

Interesting. Would the HP still open though?

A water-dropped linotype HP would be "tough"...but me thinks it wouldn't open at all.

Copper...you talking about copper powder?

[lwknight]

Some plain old tin helps the boolits stick together pretty good and still allows expansion.
Soft lead bullets lose a lot of weight even with copper jackets wrapped around them.

[qajaq59]

I can't help you with the hollow points. But in my 30-30 I use an alloy that has a BHN of roughly 11. It's cast in the Lyman #311041 with a gas check. At 50 yards it mushrooms to .57 and has virtually no weight loss when shot into fine sand at about 1800 fps. It might be worth a try for you as a hunting bullet.

[runfiverun]

the less antimony you can use the better.
cut some ww's down with pure to about 1.5% Sb and 1%Sn water drop and test.
you might just be surprised at the results.

[beagle]

Probably, a high antimony, water dropped HP would tend to shatter. I've seen "solids" break in two pieces and show definite crystalline structure at the breaks when made of high antimony content #9 shot.

You'd get expansion and breakage but also loss of weight as well due to the shattering affect and I believe our goal is to retain weight as well as encourage expansion./beagle

[Dannix]

Yeah, going to try tin. Now I just have to find a cheap source of tin. :???:

The gottcha for me on going with the +1 HP option with a NOE mold is the weight difference between the RF and HP and the, I assume, resulting different point of aim. But it may a predicable and easily compensated difference at an appropriate, <100m distance.

[runfiverun]

i doubt the deer would care if you were an inch off.

[sagacious]

A water-dropped linotype HP would be "tough"...but me thinks it wouldn't open at all.
A linotype bullet is definitely not tough. It is hard and brittle, which is the opposite of "tough." Put simply, tough means resistant to breakage under shock. Tough and hard are not the same. Glass is very hard, but not very tough. Copper is softer than glass, but very tough.

Leftiye and others have it right-- the addition of tin to lead will do what you want, in addition to keeping the antimony content low. That's your recipe for success! :drinks:

[leftiye]

Yeah, I've supposed that one might have to "X bullet" that 18 bhn 10% tin, 1% copper alloy boolit even if it was hollow pointed. Not a biggie, can do. I put the BHN in there to show what copper does to hardness.

[Dannix]

More info, from PMing with leftiye. Quotes are he's statements. Hope you don't mind me sharing your insight leftiye. :)


Tin toughens the alloy. It can be alloyed up to 10% in lead. Copper does too, but 1 to 2 percent is all that doesn't cause problems with casting. !0% tin and 1% copper yields an 18 BHN boolit.

How exactly do you add copper to an alloy as we don't get anywhere near the melting point. Using copper salts? Powdered copper?


I used the multi stranded lampcord. I cut it into 1 to 2 inch lengths, and made the 1% amount (approx. 1.6 oz per 10 lbs. - 10 lbs is 160 oz.). I added it to 1.6 lbs of 60/ 40 solder (the tin makes the copper dissolve more readily), by putting a small amount at a time onto the surface of the solder and stirring while holding a mapp gas torch on the copper. Don't put too much copper on at a time as the copper will burn (copper oxide or firescale) and then be much harder to stir into solution. Then I just added this solution to 8.4 lbs. of pure lead.

As was mentioned this tested at 18 BHN, and if shot in the 200 fps range as say a hollow point design, it would hold together very well. I've got the NOE 32 cal 125 gr hollowpoint mold, and I've just acquired a new Marlin 1894 in 32-20 caliber. Interesting!


- What temp do you hold your melt at when melting in copper? 800F or higher?
- Would propane be OK, or is he extra temp from a mapp torch needed? Need to pick up a torch for nose softening wd boolits, but was leaning towards the cheaper propane.
- 18BHN - is that waterdropped or as is?


I imagine the propane would probly work for mixing copper. I have one for cooking steaks, so that's what I use (cooks better than propane. Propane won't char beef- not hot enough). Go with adding the copper to tin (solder) I think. It's really about dissolving more than melting the copper. Witness how antimony will dissolve into molten lead which is way below antimony's melting point. I'd max out the lead pot temp wise, just stands to reason that hotter is better. !* BHN air cooled, probly won't harden if quenched - no antimony (antimony is needed to form crystals. Crystals are frozen by quenching. Thia causes hardening.)

[Wayne Smith]

It's a lot easier than that. Go up to Rotometal's logo, click on that, and order some Babbit metal that has a little copper in it. Already done. Just add the right amount to your mix to get the level you want. It is known for toughening the mix, perhaps just what you want.

[MtGun44]

Water dropped linotype would NOT be tough, it would (and IS) very brittle and will
shatter.

Bill

[geargnasher]

Thanks, Dannix & Leftiye!

Gear

[sagacious]

Tin is sort of a 'universal solvent' for most of the lead alloy applications useful for bullet alloy. A MAPP torch directed at molten tin will easily and readily dissolve the copper. Another technique that can help avoid oxidation of the copper, is to heat the copper to red heat and gradually add pieces of tin. The red-hot copper in a reducing flame will not have scale on it, and the tin will melt instantly and immediately alloy with the copper.

Copper seems an unpromising way to "toughen" lead, if we use the term strictly. Copper in miniscule amounts will certainly harden lead. Virtually all the copper in a Pb/Sn alloy will be be bound to tin, which decreases the amount of the malleable SnPb intermetallic within the lead. Also, the compound SnCu itself is rock hard and will shatter if dropped onto concrete. These properties add to hardness, and explain why some type metal alloys and bearing alloys contain copper (to increase hardness and thus wear-resistance), but in this case increasing hardness causes a decrease in toughness. Neither type or babbitt alloys are tougher than a simple Pb/Sn alloy.

[Wayne Smith]

Sagacious, does this remain true in water dropped boolits? That's the application where I have read that HP's don't shatter but remain together when a tiny amount of copper is added.

[sagacious]

Wayne,
To the best of my knowledge, adding copper to lead/tin or lead/tin/antimony alloys increases brittleness and hardness in virtually all cases, but does not contribute to "toughness", which is the resistance to breaking upon sudden impact. This would remain true for water-quenching.

The point of your question, water dropping hp's, seems somewhat curious to me. Slow cooling almost invariably contributes to increased toughness with lead alloys, so quenching seems contrary to your goal. If water-quenching provides a convenience when casting hp's, then the addition of tin is the best route, as it will be unaffected by quenching, and provide excellent toughness. Adding copper to that alloy increases hardness, but reduces toughness-- and neither seems desirable.

Like in some other applications, the exact alloy matters. One can dilute ww alloy with enough pure lead to give a good hp alloy, but quenching it would seem counterproductive. Still, one could doubtless fiddle with it enough to make it work, but there are surely better solutions to try first.

I hope this covers your question. Regards, and good shooting. :drinks:

[Wayne Smith]

It does, thanks. I'm eternally and unendingly curious. Always trying to tease out the facts from the dross.

[303Guy]

I'm with Wayne. I just have to know!

[sagacious]

Curiosity is to be solidly commended! I'm a Curious George myself, so I know where you're coming from.

[Dannix]

Thanks for your comments sagacious! This forum truly is a wealth of info. [smilie=w:

Hidden voids in castings (http://castboolits.gunloads.com/showthread.php?t=86377&page=2)
45 2.1 and BABore have posted some related comments in the above linked thread. The idea is to keep Antimony in the alloy, but stabilize the boolit in an oven at just the right temperature so when water dropped only the outside is hardened (crystallized) and the center remains soft. Naturally, the effectiveness of this technique is directly proportional with the boolit's diameter.

A pic by BABore, .480 Ruger:
http://castboolits.gunloads.com/attachment.php?attachmentid=22904&stc=1&thumb=1&d=1276609662

Seems like a good route for when proper penetration in addition to expansion is desired. Not sure how effective it would be for more medium sized calibers though or if it would expand quickly enough for anti-personnel purposes where I imagine a SnPb nosed 2-part boolit would be superior.


Seems like the more I learn here, the more I realized how much I don't know.

[missionary5155]

Good evening
The old elephant hunters "Hardened" lead with tin.. they had access to other metals to harden with but chose tin. 20-1 was a common mix and it must have worked rather well as there sure were a bunch of tuskers eliminated.
Brain shots were the choice and elefhant skuls are definatly thick and hard. So I guess if tin was the choice to do in an elephant heard it should continue to do well today.

[Dannix]

mk (or is it just m?), I've always thought alloy hardness was really all about desired velocity, with harder boolits allowing for greater velocity, ceteris paribus.

Correctly me if I'm wrong, but 8-bore, or the truly daunting 4-bore, shot pretty low velocity cartridges.

[sagacious]

Seems like the more I learn here, the more I realized how much I don't know.
As Socrates said, that's the only reliable indicator that one is actually learning. Keep on keepin on.

[yarro]

The brain shot on elephants was developed using round nose jacketed bullets bullets , refered to as solids, by Bell. He wanted to drop elephants in there tracks so he could shoot more at one time since you wouldn't have to follow them. Bell found that Spitzer bullets did not track true in the spongy bone of the skull. He went about the process very scientifically. He had skulls cut down the middle. He did the same with failed shots to determine what went wrong until he hit on the right bullet. Bell was an amazing shot and with superior spacial reasoning had the ability to know where the brain was in an elephant from any angle. The brain in an elephant's massive skull is smaller than a humans. Bell was also recoil shy and could not bear shooting the large bore doubles, which lead him to a small bore solution. Most others would have been killed rather quickly trying to take elephants with a 7mm Mauser. If you want to know more, read the books that he wrote and the ones written by others about him. You almost can't pick up a book on elephant hunting without finding a reference to Bell in it, even when it is written about another hunter.

The elphant hunters using 1 in 20 were shooting BP large bore double rifles with bullets starting in the 3 ounce range and taking heart shots, which was the favored technique until Bell developed a proper brain shot. The large projo diameter enhanced bleed out and allowed lots of tissue destruction and energy transfer. Recoil was more than most could bear or shoot well hence the preferance for putting a bullet in the heart lung area, which is the traditional method for killing most game. Sometimes lung shot animals would go for miles and miles before dying. A lot of elephant hunters had short careers, especially hunting in heavy cover. Elephants believe strongly in taking revenge on anything that hunts them or someone in the herd.

-yarro