Bullet hardness for expanding bullets ?

[JFE]

Gents,

I'd like to experiment with softer alloys for expanding bullets and would appreciate some guidance so I dont re-invent the wheel. In the past I have tended to use hard alloys simply because they worked for me, but I would like to try something softer.

How fast can you push soft alloys (say BHN 7-8) if the bullets are fitted with a GC ?

Is BHN 7-8 too soft for a PB design for velocities up to say 1400 fps ? If this is too soft, what hardness should I target that will still have expansion in a PB design ?

What hardness should I consider for a HP bullet (with GC fitted) ? What velocity range should I target ?

Thanks in advance.

Joe

[NVcurmudgeon]

Look at the sticky at the top of the "Moulds Maintenance and Design" page regarding soft point cast boolits by BruceB.

[9.3X62AL]

Ya know, we need a catchy name for Bruce's softpoint castings. I cast a vote (no pun there) for "Bruce B's Bonded Boolits", or "4B's" as codeword/acronym.

I've run air-cooled wheelweight metal past 1300 FPS in magnum revolvers with decent accuracy and no leading, both plain-based and gas-checked. I almost always employ a gas-check design in rifle barrels, regardless of boolit metal. Current exceptions are 44-40 WCF and 45-70 Springfield.

[JFE]

Thanks for the replies.

The soft point cast bullet discussion is very useful. I agree that for 'special' hunts the time taken to produce small lots is not important as few shots are taken at game. However I was more interested in casting up quite a few and the process is a little too fiddly for making up a larger number of bullets.

I have a new 458 HP GC mould that is as yet untried and I am thinking of pushing a softer lead alloy around 1600-1800 fps. From what I gather I should try to use alloys of lead and tin vs WW due to the more ductile nature of the alloy.

Views, comments & suggestions are welcome on alloy, sizing, lube to use, etc. BTW I've never cast a HP either and would appreciate any tips you might pass on.

Joe

[leftiye]

I like the hollow point approach myself. BTW, there are plenty of threads here on this subject (believe it or not about three this week). Keep looking under search. You seem to leave velocity wide open, and don't say whether you're shooting these in a pistol , rifle, caliber, etc. so you'll just have to re invent the wheel (kidding). But, you will have to experiment, and if you want to narrow the field some, it would make thangs much easier.

Pure (BHN 5-7), wheel weights and pure at 50/50 (BHN 12-14) will expand, maybe somethin a little harder. pure has to be going about 1200 fps for reliable expansion, but will probably start expansion at 1000 fps. There's a formula for speed for different hardnesses of lead, but I can't remember it.

AND there is a velocity that a given alloy will come apart in target animals this turns yer boolit into a good varmint boolit. A good game boolit needs to be tough. Tin, and copper in your alloy help make boolits tough.

Accuracy relates to boolit hardness. Softer leads mush (obturate, and/or deform)) up at lower pressures in a given cartridge. Go higher, and sooner or later accuracy dissappears. Kieth liked 20 to 1 lead/tin alloy (BHN12) and ran it at 1200 fps. Not everyone can get good accuracy with this load (even if they were to find an actual Kieth boolit to shoot). Not all guns will shoot accurately with the same pressures/ powders.

I'm on the same quest you are on. P.M. me if you want, and we can explore this further maybe.

[John Boy]

http://www.lasc.us/CastBulletNotes.htm

Approximate "Maximum" Chamber Pressure For Lead Alloys (PSI)
Plumbers lead, stick on WW 13,000 - (Black Powder Only)
Wheel weights / clip-on
25,000 - Non-Magnum handgun
loads, Rifles to 1,800 fps

Lyman # 2 (alloy varies in
Lyman cast bullet books)

35,000 - Magnum handgun &
rifles to 2,000 fps

Quench-cast WW (dropped from mould into cool water)

48,000 - Magnum handgun
& rifles to 2,200 fps
Oven heat treated WW
55,000 - Jacketed velocities in handguns and rifles with quality bore & balanced load

Bullet BHN / "Minimum" Chamber Pressure For Lead Alloys (PSI)
The formula (from the pages of HandLoader Magazine) to determine at what pressure an alloy of given BHN will obturate the base of the bullet and seal the bore. If the bullet is too hard to obturate, gas cutting usually occurs on the base band on the non-driving side of the rifling and barrel leading is likely. Simply multiply the alloy BHN by 1,422.
Example: Alloy BHN of 12 multiplied by 1422 = 17,064. An alloy of 12 BHN should be used with a load that develops a "minimum" of 17,000 psi. Need more info on minimum / maximum alloy BHN? These Glen E. Fryxell articles explain alloy BHN in easy to understand language.

[JFE]

JB - thanks. There's a lot of useful info on that site.

Leftiye - thanks for the offer and I'd be very happy to collaborate on developing this.

Additional info:

Where I would like to start is with the 458 mould I have. Its a CBE mould based on a Gould design but with a GC shank and HP plug added. It also has a plug to produce flat nose design too. I figured that a GC would allow me to gain some additional velocity and still use a softer alloy. I will be using this bullet in a couple of 45/70's - a microgroove Marlin and a Browning 1886.

I'd like to target something like 1600-1800 fps, mainly because I'm not sure that they would work well at a higher velocity. I am hoping that the bullet will be effective against medium game without shattering or too much meat destruction.

Happy to take this offline rather than bore folks with further details. If we come up with anything useful I'd be happy to post results.

Joe

Joe

[Glen]

Bullet expansion, a topic near and dear to my heart!

Cast bullets will expand nicely, if cast of a suitable alloy for the impact velocity. At slower speeds, then bullet construction needs to be modified (i.e. hollow points, soft-noses, etc.) to achieve the desired effect.

One of the nicest examples of this was a bullet that my good friend Rob Applegate recovered from his first buffalo. It was a .45-70, cast with WW alloy (Rob's WW's tend to run around BHN of about 11), and his load was pushing this bullet along at about 1650 fps. This particular bullet was recovered under the hide on the far side, expanded into the most beautiful mushroom you've ever seen (broadside ribcage shot, 80 yards).

For a picture of this bullet, go to:

http://www.leverguns.com/articles/fryxell/old_rifles_old_friends.htm

I haven't recovered any of the bullets, but the wound channels from my pet .35 Remington load (200 grain GC-FP at 2100 fps) indicate good expansion when cast to a BHN of 13-14 (I use 2 parts range scrap to 1 part linotype to make this alloy).

I have seen animals that had been shot with muzzle-loaders using dead soft cast bullets (BHN of about 6) at 1300-1400 fps, and the gaping wound channels clearly indicated that those projectiles had expanded.

A while back, someone posted over on leverguns.com a table that was taken out of Clyde 'Snooky' Williamson's "Winchester Lever Legacy" that showed minimum velocity necessary to get a given alloy hardness to start to expand. Here are some of those numbers:

5-6 BHN ...... 1150 to 1200 fps
12-13 BHN .. 1350 to 1400 fps
14-16 BHN .. 1600 to 1700 fps
20-22 BHN .. 1900 to 2000 fps
30-35 BHN .. 2300 to 2500 fps

Pushing things faster just helps expansion along that much more. Likewise, if you don't want any expansion in a given application (e.g. shooting Cape buffalo) then make sure your alloy is harder than suggested for a given velocity.

[Bullshop]

A very basic formula I use is that expansion will begin when impact velocity is equal to the bhn X 100. This is where expansion seems to begin and from there a higher impact velocity will take expansion to a higher degree.
The large caliber blunt sluggs slow quickly and when being launched at or just over this minimum expansion threshold may no longer have the minimum at impact.
Chamber pressure and muzzle velocity have little to do with expansion at the target. Its all about how fast its going when it hits.
BIC/BS

[leftiye]

Is that the 330 grain RCBS? The Lyman Gould Special is 330 grains also, and is a well established deer banger (killer). This, IIRC is at lower velocities, but expansion gets more dramatic as velocity goes up. If you go 1700 fps, you might not even need a hollow point with 14 BHN lead. 5%tin= 1to 20 tin/lead is 12 BHN, so maybe 3% antimony, too. Should hold together maybe and expand muy well at those velocities (reads kick butt) probly with only the flat point. Do test your boolits! Wet paper is pretty good for this.

[mauser1959]

While there are a lot of guys who seem to know thier stuff on this board, I would check out what Glen has to say. He is the most knowledgeable man about bullets and lubes that I have ever seen . I have read his articles for years and his PHD might not mean much to most people , but to me it means that he not only has the field experience , but also the lab results to back up what he is talking about . If I am out of line here , I am sorry as I wish no one any harm.; but he sure took me to school about bullet lubes and I figured that I knew quite a bit about chemistry. I am not saying he is elmer kieth , but he is one smart cookie when it comes to his subjects.

[Bass Ackward]

When I look through my testing records, my stuff pretty closely resembles "Snookie's" or Dan's rule of BHN times 100 under my testing conditions. All except for the 5-6 BHN which can be expanded down to about 800 fps before it get's a little iffy.

But I must add that these are strike velocities, not muzzle. Nose shape will alter the velocity required and also affect velocity loss. Bullet diameter will affect this too as a smaller shaft has less strength than a thicker one once expansion begins. The chosen target can raise or lower these numbers significantly too. The tougher the game animal, the more reliable the expansion rule or chart is, the greater the margin for error with nose shape will be too.

[Bass Ackward]

Oops.

[Bullshop]

Mauser1959
Thats OK I respect the education the man has too, but that dont mean he or anyone can know it all.
With the number of bad spelling, grammer posts I have made on this board and by my own addmition everyone here knows I have little formal education. That dont neccessarily mean I am dumb or stupid, or ignorant. What it means is that I had no family that cared when I was of school age and I didnt care eather.
My education has been of the world by doing and casting and shooting boolits is one thing I have done lots of. Even an idiot can learn to do well if enough time is spent at it.
I spend more time at it learning because its my job, making boolits and it is still one the the major interests in my life.
Now I had the feeling that you were pointing right at me with your post and I also got the feeling that you also having a higher education could never feel that someone without formal education could be your equal on any given subject. Thats OK its human nature, but its too bad because your the one that may be missing out if such a closed minded nature were to exist.
If I am off base I apologize, but being my education came from the world I have learned things about people too.
I looked at the chart Glen posted and for the most part I agree. The section for soft lead I cant agree with though. Pure lead will certanly expand at far lower velocity than listed. You can easily proove it by shooting any air gun that has a velocity of say 600 to 900 fps. These will reliably expand a pure lead pellet.
The rule I gave as I said is very general but also very close to true, but at the higher end of boolit potencial will show greater divergance.
There was a kind fella from this board that PM'd me about my spelling/grammer problem. He informed me that because of it that no one can take my posts seriously. I told him the important thing was to look at what I said not how I said it. If no one is taking me seriously then they are loosing out on the benifit of my experiance.
In my life experiance I have learned to listen to anyone that has 30+ years experiance at something I would like to learn about. Many years ago when I was working in the woods in SE Alaska learning to fell timber I saw many die trying to learn on thier own and too stuborn to take advice from thoas with experiance. I have always been humble enough to admit that someone may know more about something than I do especially if they have many many more years experiance than I even if they never went to school.
BIC/BS

[floodgate]

Bullshop:

You have NOTHING to apologize for!!! I went the whole nine yards thru college and grad school, and you and others here have taught me at least as much as I learned there. Plus, you invented Bull Plate lube!

Guys, if you get hung up on grammar and spelling, try reading these posts out loud. Like many of our Founding Fathers, Saml. Colt and other "greats', BS writes 'em like he wants 'em heard. And the "Jrs." have had a great pair of teachers, as is easily seen from their posts. The rest of us should do as well...

floodgate

[45 2.1]

Plus, you invented Bull Plate lube!


Actually, I think he found it, since it is meant for another use.

[Larry Gibson]

When I look through my testing records, my stuff pretty closely resembles "Snookie's" or Dan's rule of BHN times 100 under my testing conditions. All except for the 5-6 BHN which can be expanded down to about 800 fps before it get's a little iffy.

But I must add that these are strike velocities, not muzzle. Nose shape will alter the velocity required and also affect velocity loss. Bullet diameter will affect this too as a smaller shaft has less strength than a thicker one once expansion begins. The chosen target can raise or lower these numbers significantly too. The tougher the game animal, the more reliable the expansion rule or chart is, the greater the margin for error with nose shape will be too.

Everyone else's posts provide good information but Bass Aackward's post hit it short, sweet and to the point. Expansion depends on the target composition, the bullet caliber and nose design, the hardness and maleability of the alloy and the striking velocity. I've got good controlled expansion down around 700-800 fps up through 2200 fps.

Larry Gibson

[45nut]

Thats OK I respect the education the man has too, but that dont mean he or anyone can know it all.

Belittling others "lack" of a piece of paper shows very little class. I am attending the hardest university on earth, the school of hard knocks and the people that have helped the most are not those with formal degrees, rather they are the people that are much like me and have an idea of the fight that life can be when those with "ejucashun" are the ones most likely to kick you when you are down instead of giving you a hand up. I would trade 50 of those with phd's for another with a life as rich as Dan's when the contempt vs sharing and helping is measured at the Pearly Gates.
This board is based on the principle of helping, sharing and real life experience and debunking the falsehoods encountered in our craft. That is paramount in the success we have here, not belittling others because someone lacks a certificate on paper. Theories and perceptions be damned, show me real hands on practice and not a keyboard warrior. That is where it counts.

[leftiye]

Glen has helped me with several critical pieces of information when I got in over my head in the past. He's very considerate of us less knowledgeable people. So has Bullshop. I for one would not like to put my knowledge up against either one of them. Nor is there any reason to do so, neither one of them has any currency in this issue. Actually, I thought Mauser might be taking issue with my post. If so, well good enough.

[JFE]

Gents,

thanks to all for taking the time to post and for the valuable feedback. There is a huge amount of experience on this site and more importantly people prepared to share their experiences and help inexperienced people like me out. Thanks for sharing. I now have info to help shorten the development process.

Leftiye - the mould is a CBE mould (made in Oz). It is loosely based on the Gould design and in stock form (solid FN) it casts 360gr. However I had Jim add a GC shank and a HP. I think he said that it should come out something like 380 gr. The HP is quite large and deep.

I will try to cast some over the weekend and take some photos of the bullets and the mould.

Joe

[waksupi]

I agree about Phd's. Generally educated completely beyond thier intelligence.

[MT Gianni]

I have met a few that were not but they were a very small number. Gianni

[Lloyd Smale]

I too have been called on the carpet on here and other fourms for my spelling and sentence structure and could care less. If you dont want to read my post dont. Only thing worse then ******* is a smartass!! Id rather read a post with half the works mispelled that has some good knowlege in it then a well written I agree with someone else post. Glenn this certainly isnt meant for you as i respect your writings alot and you know i think the world of Rob. They just dont come any better then him. Still waiting for that casting book to come out!!!

[Bass Ackward]

Only thing worse then ******* is a smartass!!


Hey, I resemble both those remarks!!! Thank God for spell checker. :grin:

I think Mr Mauser has a case of hero worship. And that's OK. Glen is a carrier of the torch. Gosh, once upon a time Veral Smith was my hero too. :grin:

[SharpsShooter]

PHD??? I gots a PHD. It is hung upin the shed. Round here we just calls em post hole diggers though.

SS

[Glen]

Bullshop -- You raise a good point about the expansion properties of soft lead. But, as a counter-point, let me point out that an airgun pellet is generally hollow, and the lead is very thin, and its expansion behavior is coming as much from the thinness of the walls as much as it is from the softness of the lead. If you look at that expansion of a solid lead rifle bullet, I think you really do need to get the impact velocity up over 1000 fps (as some of the other folks have pointed out, this is going to be somethat dependant on nose shape). Other than that, I think the data in Snookie Williamson's table is pretty much on the money.

[leftiye]

Moderation in all things (heh, heh). I was just reading Lloyd Smale's thread about flat noses. They kinda focused on 30 cals, saying that round noses don't do adequate damage in game unless fired rather hot, and cast rather soft. Disparaging the advantage of a ballistically slick nose in favor of flat noses.

Here, as there, my thoughts strayed to "how much better it would be if the boolit were moving fast enough to expand when it introduced itself to mister deer, elk, buffalo etc". A lot of discussion there involved big bore pistols and rifles. This means heavy boolits. Higher velocity there means heavy recoil. Unless you enjoy pain and are fortunate enough to be able to still shoot straight in high recoil situations, then lighter boolits are a godsend, maybe a necessity.

As bore diameter goes down, a boolit that would be light for caliber (300 grain in a 45-70) starts to have a ballistic coefficient again. The boolit weight necessary to endure recoil at 2000fps. now has some ranging ability. This in a 375, 40, or 44 caliber. Now you have everything but the flatpoint, so why not one of bruce B's two alloy soft points (with linotypr bearing section) with a round, hollow or even spire point? Or maybe a .35 cal 250 grainer at 2200 fps?

[Bullshop]

I dont know Glen, I have to wonder. I make lots of pure lead boolits for lots of folks. Too many times my fat fumbling fingers loose control and drop a freshly lubed boolit to the floor or worse yet knock off a whole tray that I am working on. The flight to the floor is short, prolly less than 4 feet. I have not a clue what kind of velocity those boolits excelerate to during thier flight but my guess is something far less than 300 fps. This I am assuming after reading of a conclusion by the US gument through testing had determand that the minimum velocity to penitrate human skin/tissue was 300 fps.
Since dropping these boolits on a bare foot does not penitrate my skin I assume they are traveling at less than 300 fps at that point in thier travel.
OK then if we agree on that I have to wonder why each time one of my pure lead boolits impacts the floor it becomes expanded beyond use of its intended purpose.
Not being a sientist I admit to not knowing lots about how low velocity impact into materials of differant hardness will affect the outcome of a pure lead boolits impact.
I do have to wonder though how an impact of the same boolit into the same material will react at higher velocity. For instance shooting into water. Water as we know it at our normal velocity is soft but if we jump off a bridge thats 500 feet over the water where our velocity has increased a bit then the water has a much differant affect on us, the projectile in this case. How about this, shoot that low velocity pellet gun at water at an angle and it will simply stay right where it hits but if you increase the velocity the water acts as if it were hard as concreat and the boolit bounces off.
Seems we would have to come up with some kind of rating systam that tells us at what impact velocity our target becomes hard and at what it is still soft. Thats really it the target weather it acts hard or soft. The boolit cast in pure lead will expand if the target acts hard at an impact velocity far less than the figures given in those tables.
So yes my large caliber blunt nose pure lead boolits do expand at a very low velocity. Unless you can explain to me in a way I can understand I have no other choice than to believe otherwise.
BIC/BS

[Scrounger]

It's relatively easy to estimate their velocity, Dan. The acceleration of gravity (falling objects) is 32 feet per second per second, which means things fall 32 feet in the first second, sixty-four feet in the second, 96 feet in the third, and on and on... A fall of three feet means they would not exceed the velocity of 32 FPS, and probably a bit less than that even. (Pardon me, too much time on my hands...)

Rereading your comment...We can estimate the force such an impact places on your bullet using the formula E=MV2/450400. So weight in grains times the velocity times the velocity divided by 450400. So a 400 grain bullet would be 400 times 1024 divided by 450400, which is 0.9 foot pounds. Obviously there are other forces involved since the bullets are damaged. Maybe Felix can figure that one out. Only thing I can think off is that the force is not applied in a uniform manner to the entire bullet but to only that small part of the bullet that impacts the hard surface. The BH of pure lead is supposed to be 5 and require about 7000 foot pounds of force per square inch to deform it. The force from the fall is very small, less than 1 ftlb, but if it is applied to a very small part of the bullet, then its effect must be greatly magnified. I don't think it's possible to break the laws of physics...

[redgum]

I have played around in the past with some swc/hp's cast by a friend in an Ideal mold using straight W/W. I found that when driven hard from 357 Mag loads they tended to fragment at the nose and over penetrate. I tried some at more modest velocities in .38spl+p cases (with 4.5g Win. 231) and found they worked much better.
The 1st pic shows some of the recovered fragmented bullets and in the 2nd there is an "Ideal" one on the right, and the 2 on the left were 125g conicals that I drilled after casting. Sorry for the quality of the first pic, only had a camera phone handy.

http://i141.photobucket.com/albums/r49/redgum94/1_2_3.jpg

http://i141.photobucket.com/albums/r49/redgum94/DSCF6633.jpg

Regards, R

[garandsrus]

Bullshop,

Your boolit dropped from 4ft is going 16fps when it contacts the floor. It will make the fall in .5 seconds.

John

[Bass Ackward]

Seems we would have to come up with some kind of rating systam that tells us at what impact velocity our target becomes hard and at what it is still soft. Thats really it the target weather it acts hard or soft. The boolit cast in pure lead will expand if the target acts hard at an impact velocity far less than the figures given in those tables.BIC/BS



Everyone could be right. It really depends on their definition for expansion.

Someone looking for a twice the caliber increase is going to have a much higher velocity threshold for all those hardness numbers.

Thinking about myself, my definition is directly affected by my testing. Someone else using a different medium is going to see different results. Kinda like drawing the line between when obturation progresses and becomes deformation.

Want to be safe, use a higher number or modify the nose structure to promote deformation that we now want to call expansion.

[Bullshop]

Yea thats kinda what I was saying, the media weather its hard or soft, or weather it acts hard or soft at the impact velocity in question.
Lets say that two people are testing the same boolit cast in the same alloy and shooting at the same velocity.
They each shoot ten deer, one never hits a bone and one hits a bone each time. The fella that never hits bone comes to the conclusion that because his boolits did not expand that it will take more velocity than what he used to get expansion. The other fella that hits bone each time finds differantly that this velocity is quite adiquite for expansion. Yup the media is it hard or soft and even if soft at some velocity it will act hard. Maybe the velocity at which soft acts hard is what the chart refers to.
Glen said I made a good point with the air gun pellet analagy then he made a counter point. To that I can only think that is exactly what we are doing when we hollow point a boolit, thinnig its walls so that it will expand at a lower impact velocity.
Also what Scrounger said about not being able to change the laws of phisics, and that the expanion occured from the fall to a small point on the boolit. Well is that not what we are making with the hollow point also?
So you see boolits cast of pure lead will expand at far less impact velocity than that chart listed and I think it rather obsurd to say that across the board it takes a minimum of --- fps for a pure lead boolit to expand
Another point I wanted to make was about a test I did with a very light loaded 45 acp with 180 hp boolit. The media was a cotton wood block. Shooting into wood can be a big surprise. You think of it as a hard madia and it is but it has the effect of acting like a gun barrel in preventing expansion by holding in the sides. I often recover HP jacketed bullets from wood that have failed to expand.
Anyway this test with the 45 was done with one boolit fired normaly and one had its nose cavity filled with boolit lube. The normal round had slight deformation but the round filled with lube is completely expanded. I have these two boolits saved and hoped to post a pic. The problem I have there is I have to get BS Mom to help with that and she is busy schooling the sprouts.
I will try later, now I have to go get a load of hay.
G'Day to all!
BIC/BS

[floodgate]

Bullshop:

"Anyway this test with the 45 was done with one boolit fired normaly and one had its nose cavity filled with boolit lube. The normal round had slight deformation but the round filled with lube is completely expanded. I have these two boolits saved and hoped to post a pic."

That principle has been used for many years to get expansion: packing the hollow point with a solid plug (like the Hoxie bullets of the '20's, with a steel ball set into the nose), or filling a large hollow point with an incompressible fluid (oil, wax - even water) and closing it over. The solid or fluid is shoved back on impact and starts spreading the nose sideways, after which the normal mushrooming proceeds naturally. A good way to get a "meplat" effect from a "streamlined" bullet at moderate velocities.

I LIKE the way you think!

floodgate

[Bullshop]

Here ya go. they are not the greatest pics but you can see the differance. Velocity was about 700 fps fired from a 45 acp.
http://img.photobucket.com/albums/v239/bullshop/P1010002-1.jpg
http://img.photobucket.com/albums/v239/bullshop/P1010001-2.jpg