Hollow-point alloys for moderate velocities

[John in PA]

I just picked up a Lee .429-200RF mold hollow-pointed by Erik at Hollowpointmold.com. I have the ability to blend alloy and would like suggestions for maximum antimony content that will still allow function of the hollowpoint at moderate (say 850-1050 fps) velocities. I'd like to add a bit of antimony to my 1:20 tin:lead mix to toughen them up a bit, but am concerned about wasting the effort to make the hollowpoint if it's not going to open up.

http://www.hollowpointmold.com/forsale/sale-pictures/208.jpg

[bhn22]

I wouldn't go over 8-10 bhn for the low speed loading, and perhaps a max of 12 for the faster load. The problem with antimony is that it alters the crystalline structure on the alloy, and too much of it will either not allow any expansion, or make the bullet fragile enough that it fragments. What you really need to do is experiment with your mixes and fine tune your alloys to your results. Test your hollowpoints in soaked newsprint to start, or perhaps ballistic gelatin. I'm not personally convinced that milk jugs full of water are the best test medium, but since I've never tried it... :grin:

[Forrest r]

Antimony really isn't the greatest thing for hp bullets, it can make them brittle.

Here's a link to a 1953 american rifleman article, it's showing/testing expansion with different 44cal lead hp's made with different alloys & how they performed at different speeds.

http://www.goodrichfamilyassoc.org/44_Special_Articles/44%20spl%20-%20may%201953%20american%20rifleman.pdf

I've always used these #'s as starting point to test hp bullets.

40 to 1 ='s 8bhn/800fps
20 to 1 ='s 10bhn/1000fps
10 to 1 ='s 12bhn/1200fps

Very nice mold by the way, it reminds me of the mihec 640 mold that I cast hp's for the 44cal's with. 200gr hp's can be extremely devastating at the speeds you're asking about. I use 200gr hp's in the 45acp & a snub nosed 44spl . The 200gr hp's that I cast/use in 44cals.

97597

forrest r

[jmort]

I really like 20 to 1. At rifle velocities keeping the antimony and tin balanced makes sense like Lyman #5. Great article. After reading that, the 10 to 1 looks nice for around 1200 fps as you noted.

[John in PA]

So even W/W-metal-levels of antimony (like 1-1.5%) will pretty much eliminate expansion of the HP?

[USSR]

I also like 20 to 1. I use this alloy for .45 Colt 265gr HP's that are driven between 1000 and 1100fps.

Don

[jmort]

I bet that works real good.

[runfiverun]

ww alloy doesn't hinder the boolits ability to mushroom.
it causes the mushroom to shear away at weak points in the alloy.

if you eliminate either the tin or the antimony you can get a boolit to mushroom perfectly and remain as a softer alloy.
the trick is in how you form that boolit.
swage a 5% antimony alloy boolit and it is softer and more malleable than one containing 5% tin.
however tin will soften a lead alloy over time if used alone.
the tin alloy will remain more fluid when it is used to cast the boolit.
it's the SbSn matrix that causes a cast boolit to become more prone to shearing and away from the desired malleability.
if you don't think tin is brittle, bend a piece of tin alloy and listen to the popping and creaking, that is the tin molecules breaking apart.
bend a low antimony alloy and you hear nothing, the antimony actually allows the lead to flex and slide across itself once the antimony is broken down within the alloy.
if it's swaged or work softened it's actually more malleable than a tin alloy is.

[jmort]

Antimony, up to 1.5% makes a great lead alloy, but after that you need tin to keep the antimony in harmony with the lead. I think?

[Wolfer]

If your alloy is already 5% tin I think you would have to add at least 5% antimony to keep the balance. I think that would be pretty hard.

I think you would have a hard time beating plain old 20/1 for a HP at your velocity.

[telebasher]

I just picked up a Lee .429-200RF mold hollow-pointed by Erik at Hollowpointmold.com. I have the ability to blend alloy and would like suggestions for maximum antimony content that will still allow function of the hollowpoint at moderate (say 850-1050 fps) velocities. I'd like to add a bit of antimony to my 1:20 tin:lead mix to toughen them up a bit, but am concerned about wasting the effort to make the hollowpoint if it's not going to open up.

http://www.hollowpointmold.com/forsale/sale-pictures/208.jpg
I just purchased one of those in original solid nose and cast up 400 or so out of ACWW and when they cooled I put the digital calipers to one and it showed 428.9. I measured about twenty and the the largest was 429.3 with the average at 428.7. I wanted to try in my new Ruger 44 SPL but they fall thru the cylinder! Anybody else tried this mould. Have several hundred 429421's and some 429415s so I am good to go . Didn't mean to hijack this thread but just cast those Lees last Thursday and was fresh on my feeble mind.LOL

[John in PA]

Haven't cast any yet. Sure hope mine come out at least .430" !!! I'll be using 5% tin/95% lead for starters, I guess.

[Bigslug]

I'm not personally convinced that milk jugs full of water are the best test medium, but since I've never tried it... :grin:

I did, just a few days ago. I don't have any illusions about it being even slightly scientific, but it's a baseline that doesn't require an elaborate setup. Bullets were made with the hollowpoint pins in the NOE 429421 from WW + 2% tin (235 grains) driven out of my Blackhawk at about 1400 fps. The nose DID NOT stay attached in the slightest, not that I really expected it to, but it DID take four 1 gallon milk jugs and the leading wall of the fifth to stop the rear section, which was basically just the driving bands. While obviously not what you want a hollowpoint to do, and obviously not a ringing endorsement to use antimonial alloys for that purpose, I'm not really wanting to call the result a bullet failure. All the same, I think if I do continue to mess with HP's (and I'm not sure that I am), it will probably be with the tougher binary (lead/tin) alloys

[fecmech]

I'm not sure why you want to "toughen" your bullets with antimony. At 20/1 they are plenty strong enough for the velocities you stated (850-1050 fps). Actually too tough IMO for the 850 fps range, I'd be more inclined to use 30/1 there if you want expansion.

[Outpost75]

So even W/W-metal-levels of antimony (like 1-1.5%) will pretty much eliminate expansion of the HP?

In my experience wheelweight alloy when hollow pointed requires 1300 fps for reliable expansion, so is ineffective until you get to full charge loads in a .44-40 rifle, or. 44 Magnum revolver, but rather than mushroom, it then tends to blow the expanded nose off in fragments. If you want classic mushroom expansion with 80%+ weight retention use NO antimony, and cast not harder than 1:20 tin/lead.

If you need stronger alloy for high velocity rifle use, heat treated, dilute antimony alloys will provide hardness with ductility, 1 pound of wheelweights to 7 pounds of plumber's lead, heat treated at 450 degs. F for 4 hours then water quenched, and baged, then immediately cold soaked in the freezer for 14 days at below zero F. for 28 BHN, will stand 2200 fps in the .375 H&H, give double caliber expansion of #375449 without hollow pointing, and retain 80% or better of original weight.

[jmort]

Water is tough on bullets. It will open a Boolit that will not open up in the real world. If your Boolit will not expand in water it will not expand in the real world. Shooting into water is fun.

[lwknight]

In my limited testing, I found that 2-3% tin works great with 95 % weight retention.
Also 1 to 1.5% antimony does not hurt a thing as long as 2 to 3% minimum tin is included.
In fact, I think that the low antimony might even help after the bullet ages several years. It will take forever to prove this theory.

I believe that the low antimony will keep hardness without brittleness and the age soft tin will still do its work for weight retention.

[landers]

I have not been able to find an alloy with any % of antimony that will hold together. They always seem to come apart, too brittle, so I now only use 1:20 for my hollow point boolits and could not be happier with the results.

Landers

[kevmc]

From Ingot to Target:
A Cast Bullet Guide for Handgunners
Glen E. Fryxell and Robert L. Applegate

Excellent coverage of this topic.

Kevmc

[Forrest r]

Haven't cast any yet. Sure hope mine come out at least .430" !!! I'll be using 5% tin/95% lead for starters, I guess.

Allot of caster here use a 50/50 mix of nothing more than coww/pure lead. I would give that a try 1st & see if that suits your needs.

Here's a link to a guy that allot of people quote on this website (Glen E Fryxell), he wrote an article on casting/using/testing hp's.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CCkQFjAA&url=http%3A%2F%2Fwww.sixguns.com%2Fcrew%2Fcast.htm&ei=ZEQLU6PQHoTYyQGk-4D4DA&usg=AFQjCNFgWwjfxLdrBpIygRigdRbPGLf21g&bvm=bv.61725948,d.aWc

His alloy "alloy I like to use" of 9# of ww's, 1# of pure lead & a couple ounces of tin would be easy to duplicate and test. It's giving him a 12bhn alloy 95%lead/3%antimony/2%tin. Which if you also notice keeps him quoting that all the different hp bullets he casts/uses do their best in the 1100fps+ range and most of them in the 1200fps range. Along with several quotes that at slower speeds a softer alloy would be better.

As you can see from this link & other posts from people on this website, a small amount of antimony is ok. It doesn't take long for the bullets to get brittle when antimony/tin get together. If you have coww lead alloy laying around I'd try 50/50 ww/lead along with 40/60 & 60/40 alloys. 1 of them should get you close to where you need to be & allow to to fine tune the bullet with ww or tin to the speed/acceptable accuracy/performance of your hp/firearm combo.

Enjoy your new mold.

forrest r

[USSR]

...I found that 2-3% tin works great with 95 % weight retention.
Also 1 to 1.5% antimony does not hurt a thing as long as 2 to 3% minimum tin is included.


+1. I also use alloys with 1 - 1.5% Sb and around 3% Sn for HP's without issues.

Don

[lwknight]

I think a good many people are just too cheap to actually use a substantial amount of tin. All they talk about is the world famous 50/50 mix. Maybe they should actually try some 50/50 bar solder in the mix.
Just sayin.