How soft does your alloy have to be to get hollow points to reliably expand?

[Russel Nash]

Yeah, just like the title says.

I have had some MiHec molds for about 10 years now just sitting in a drawer.

If I get back into casting boolits, and I use those hollow point molds, I am just wondering how soft does my mix need to be.

This will be just for 9mm, .40S&W / 10mm, and .45ACP.

So maybe at most 1,200fps on the high end. On the low end, for the .45ACP probably like around 800fps.

I will plan on powder coating these.

Thanks in advance!

[lancem]

I don't have the answer but I wondered the same thing and have cast some with pure lead that I have PC'd but have yet to test. I have an old box of 38 special factory loaded with the old FBI load and they seem to be close to if not pure lead.

[AnthonyB]

My experience with the Lyman 358429/439 showed that WW alloy was perfect. I didn't have a tester then, but just used the same alloy as everything else. No need for special alloy in that one, and I've used the same in all my MP molds. You might want to add a little tin if using WW. If I were buying alloy I'd try Rotometals 1/20.
The differing HP stems will also play a role in how much the boolit expands/holds together.
Tony

[atfsux]

The EASY answer is use plain pure lead, but use a gas check. The softer the lead, the more likely to expand. But use too soft a lead, and you have issues with leading, which coating will not always solve. Most people do OK with a Brinell of 10-12 if velocities are above 1000 fps. But drop below that, like with .45 or .38 and expansion gets iffy.

Straight Shooters Cast Bullets Co. produces one exactly like this for use in duplicating (reliably) the modern version of the legendary "FBI load". https://sscastbullets.com/product/35...-check-hi-tek/ They cast a 158 grain LSWCHP, coat it with Hi-Tec, then give it a gas check. I have loaded this projectile to 850 fps in my S&W 686 4inch and fired it into water to test expansion and it worked very good.

[Gamsek]

MiHec HP moulds, 9mm, 357,44.

20:1 alloy.

850 - 1100 fps, reliable expansion.

Going higher with antimony, petals may break.

[dverna]

MiHec HP moulds, 9mm, 357,44.

20:1 alloy.

850 - 1100 fps, reliable expansion.

Going higher with antimony, petals may break.

Nice!!

[Gamsek]

Yeah, just like the title says.

I have had some MiHec molds for about 10 years now just sitting in a drawer.

If I get back into casting boolits, and I use those hollow point molds, I am just wondering how soft does my mix need to be.

This will be just for 9mm, .40S&W / 10mm, and .45ACP.

So maybe at most 1,200fps on the high end. On the low end, for the .45ACP probably like around 800fps.

I will plan on powder coating these.

Thanks in advance!

900 fps vs

1200fps MP 432-640 devastator deep HP

No leading. Did not try how accurate it was at 1200 fps but I could hit what I was aiming on.

I usually use 850-950 fps for my everyday day load.


Some eye candy with MP HP’s.

[Gamsek]

900 fps vs

1200fps MP 432-640 devastator deep HP

No leading. Did not try how accurate it was at 1200 fps but I could hit what I was aiming on.

I usually use 850-950 fps for my everyday day load.


Some eye candy with MP HP’s.

The 1200fps after. MP 432-640 devastator

[Rickf1985]

I didn't even realize you were allowed to own a pistol in Europe let alone one with hollow points. Nice layout.

[Russel Nash]

MiHec HP moulds, 9mm, 357,44.

20:1 alloy.

850 - 1100 fps, reliable expansion.

Going higher with antimony, petals may break.

So something like this:

https://www.rotometals.com/1-to-20-b...tin-5lb-ingot/

???

[Gamsek]

So something like this:

https://www.rotometals.com/1-to-20-b...tin-5lb-ingot/

???

Yes. I use this alloy also for all my subsonic .308” cast bullets. Pure lead with 5% tin.

I settled on this alloy after performing many expansion test with combination with how accurate it is on target. Purpose: hunting small animals and achieving easy expansion and nice mushroom.. It works.

You want fragmentation go harder with tin and antimony….




Last photo, purple is 10% tin (10:1). Harder but expansion at 1250 fps was less. .300 BLK

[Slugster]

Great looking boolits. Very nice pics too. You guys are pushing me pretty hard toward powder coating.

[Russel Nash]

Yes. I use this alloy also for all my subsonic .308” cast bullets. Pure lead with 5% tin.

I settled on this alloy after performing many expansion test with combination with how accurate it is on target. Purpose: hunting small animals and achieving easy expansion and nice mushroom.. It works.

You want fragmentation go harder with tin and antimony….




Last photo, purple is 10% tin (10:1). Harder but expansion at 1250 fps was less. .300

BLK

Thank you sir!

I thought maybe I messed when ordering an HP mold from MiHec for a .308 boolit with NO gas check.

I can’t remember the weight it is supposed to drop at. Probably something middle of the road like 130 to 150 grains. I lived in Illinois at the time which is NO suppressors.

So I didn’t see the point of buying a 200+ grain mold.

I wasn’t going to be shooting subsonics.

I live over in Missouri now, so that suppressor thing or issue I had before might be going away.

[contender1]

Bullet expansion is a subjective thing.
The medium it's shot into, the velocity, and the alloy all come into play.

I've seen hollow points (cast ones,) not expand, expand nicely, and also come apart. It's all about the variables.

[doghawg]

I tried using wheelweights for Lyman 358439. Out of a 4" revolver at 1100 fps they gave no expansion in water jugs. From a rifle at 1550 fps they shattered. In my opinion skip the antimony and be prepared to use some tin in the alloy.

[Rickf1985]

Gamsek, what are you using for a backstop to be able to catch those bullets so cleanly?

[Gamsek]

Gamsek, what are you using for a backstop to be able to catch those bullets so cleanly?

Soaked newspaper, balistic gelatin and big 20 liter water jugs, always backed by some dry paper which acts as a backstop for rifle cast bullets. Most of rifle cast bullets were then tested on game, European roe deer, foxes and even one chamois.

[fredj338]

It depends a lot on the HP design & your vel. I do pretty well with 20-1 lead/tin from 1000fps to 1300fps, depending on HP design. Below 1000fps, going to 25-1 seems to work well down to 800fps but again, HP design matters. I try to qavoid antimony, makes the bullet brittle & the HP frags & you lose petals above 1200fps or so, again depending on HP design.

[Forrest r]

Impressive as usual Gamsek!!!

As others have stated, it depends on the bullet & hp design. But when you do find an alloy that works, it will suit you well for 90%+ of your hp needs.

I can not say enough good about Mihec molds and the multiple hp pins that come with them. The ability to cast bullets with different pins is priceless. I cast these 432-256 hp's using 4 different pins in the 4-cavity mold/same alloy/same casting session (penta point, large hp, small hp & swc not shown).
[IMG][/IMG]

Before I would have to buy lyman molds with small or large pins or install my own pin to make different sized hp's in the same bullet for testing. Did the same thing with the forester hp tool that came with a 1/16" & 1/8" drill tool. I'd also use a 9/64" center point drill to put hp's in cast bullets. I used that 9/64th " center point drill to put the hp in this hb swc bullet turning it into a hp hb swc doing 1000fps.
[IMG][/IMG]

With those 3 hp bullets pictured above you can use the same alloy and test different velocities to see where they fail velocity wise.

That hp hb swc was cast with a 8/9bhn alloy which is what I get from cleaning +/- 150# batches of berm lead (bullets). I typically end up with 150# in and 100# of clean ingots out. I like to make batches of alloy in 100# batches, tends to lead to better consistency.
[IMG][/IMG]

That 8/9bhn range scrap is pretty soft, a 148gr cast hbwc dug out of a bowling pin/800fps load in a 38spl.
[IMG].[/IMG]
Same alloy and a cast 220gr hbwc turned backwards and shot out of a snubnosed 44spl/1000fps.
[IMG][/IMG]

Same alloy used as cores for home swaged jacketed hp's/1100fps hits in wetpack.
[IMG][/IMG]

Dug these out of the berm, 200gr hp's (penta & round) in the 1911/45acp doing 1100fps+.
[IMG][/IMG]

Much over 1100fps I have to use a small holed hp with that 8/9bhn alloy. Which leads me to think about what I'm actually trying to do. To many gun rags have come up with the need to have perfect expansion and weight retention. I get the weight retention for penetration with lighter bullets.

But at the end of the day I prefer to use hp's in larger/heavier bullets & could care less if the nose frags or a pedal falls off. Yup, too bad there 3/4/5 wound channels and +/- 150gr core of that 250gr hp hit home. Same with this 180gr hp in the 308w doing 2400fps+. If you think that that nose falling off or fragging stops the core of that bullet from penetrating. You better guess again.
[IMG][/IMG]

At the end of the day you really don't need some "special" alloy. Something as simple as stick on ww's is an excellent to start your testing. A link to a 1953 nra article on hp's and the alloys used in the tests.
https://www.goodrichfamilyassoc.org/...20rifleman.pdf

The 8/9bhn alloy I use for 90%+ of my casting/shooting needs. It's basically a 30 to 1 alloy.

[mnewcomb59]

Don't be afraid of antimony. The trick is matching your antimony and tin by weight in the alloy. When they are equal you will get 100% weight retention at some certain 300 fps impact window based on your HP cavity geometry. Antimony-tin-lead alloys give controlled expansion within a 300 fps window. Pure lead just mushrooms more and more as velocity increases. Pure lead is good for HPs from 700-900 fps and after that you want a harder bullet. If you want to shoot a HP at 1500 fps muzzle and expect impacts from 1200-1400 fps, pure lead will leave you low on penetration. I have seen pure lead 45 Colt HPs penetrate less than a 22 LR HP (9" ballistic gel, equal or less than a 380 JHP) because they expanded to 80 cal with 100% weight retention like a big ol' parachute. I have also seen 11 BHN 2-2-96 AC solids fail to exit deer at 1900 fps impact speed. It all boils down to penetration. Does it penetrate enough for self defense or hunting? Penetration is controlled by final expanded diameter. You have to test your bullets for expansion and penetration every time you cast a new batch unless your lead is all melted in a 300 pound propane melter or something beforehand.


If your alloy has 2% antimony you need 2% tin. With HPs my preferred alloy changes with velocity and HP shape. Pure lead only penetrates well up to about 900 fps. From 900-1050 I like 1-1-98. Then from 1050-1200 fps I like 1.5-1.5-97 AC or WD or 2-2-96 WD or AC depending on twist rate (9mm 10" vs 357 18.75") and sectional density (lower SD gets harder lead so its expansion is more controlled). From 1200-1500 fps you need 2-2-96 WD at 420 degrees for about 14 BHN or 3-3-94 AC and HP cavity shape is critical. Too deep or too thin of walls will affect weight retention. Above 1500 impact velocity I shoot solids.

I have seen that fast twist 9mm is the very hardest cartridge to get a plain base lead HP shooting well. The softer lead means the case can swage the bullet down easily. The extremely fast twist is fast enough to shoot a 300 grain .355 bullet at subsonic speeds and is spun up to TRIPLE the RPMs needed to stabilize a 124 gr bulllet. The soft lead wants to swage in the case and skid on the rifling. I have settled on 2-2-96 powder coated water dropped from 420 degrees for 14 BHN. I shoot light loads that are barely above minor power factor and recovered bullets still show skidding all the way to the base and some gas cutting of the powder coat. The bullets show great expansion to .64 cal and decent enough penetration at 13" ballistic gel or nearly breaking out of the 3rd milk jug. 1.5-1.5-97 WD at 430 degrees is a little too soft for the 9mm minor HPs and shows significant skidding in my 5r 10" twist pistol barrels. Strangely enough my 10" microgroove Marlin Camp 9 shows NO SKIDDING with the same exact loads with 1.5-1.5-97 WD. I guess there really is something to the old marketing that microgroove really does have more grip on the bullet.