? about alloys

[Southpaw 72]

I'm using a 97/2/1 alloy water dropped in my 454. Good accurracy and no leading.:drinks: Any one care to guess what the hardness might be? How hard can I push it?

[fisheadgib]

I'd like to think that if you know your formula, then you would know what your hardness should be. How fast are you pushing what weight and style of bullet?

[Southpaw 72]

325 gr gc @ about 1200. First alloy I mixed was equivalent of Lyman #2. I added lead to get to this. Would like to get to about 1400.

[fisheadgib]

Your alloy sounds a little soft for the pressure of a full power 454casull load. That mixture would be in the neighborhood of 7 or 8 BHN and is kinda on the cusp of being too soft for that velocity. If it doesn't lead, good on you but too soft of a bullet in the casull can increase flame cutting of the topstrap. A hot load with too soft of a bullet will not allow the pressures to get high enough to achieve complete combustion of a large charge of slow burning powder and some of the powder that is causing that flame beyond the muzzle is also eroding at the topstrap. I load a 300gr RNFNGC (22BHN) that actually ends up at 308gr once it's lubed and gas checked and I push it at 1630fps through my 454. That 7 or 8 BHN that you're getting would be more appropriate for 45 colt loads than 454casull loads.

[220swiftfn]

Your alloy sounds a little soft for the pressure of a full power 454casull load. That mixture would be in the neighborhood of 7 or 8 BHN and is kinda on the cusp of being too soft for that velocity. If it doesn't lead, good on you but too soft of a bullet in the casull can increase flame cutting of the topstrap. A hot load with too soft of a bullet will not allow the pressures to get high enough to achieve complete combustion of a large charge of slow burning powder and some of the powder that is causing that flame beyond the muzzle is also eroding at the topstrap. I load a 300gr RNFNGC (22BHN) that actually ends up at 308gr once it's lubed and gas checked and I push it at 1630fps through my 454. That 7 or 8 BHN that you're getting would be more appropriate for 45 colt loads than 454casull loads.

He's water dropping, so it's quite a bit higher than 7 or 8..... My guess would be around 18 or so, but that's a WAG.


Dan

[R.M.]

Using Bumpo's alloy calculator, it would be 10.7 air cooled.

[Southpaw 72]

Using Bumpo's alloy calculator, it would be 10.7 air cooled.

Where can I find this? If it's at 10.7 ac, I should be ok water dropping these.

[badbob454]

He's water dropping, so it's quite a bit higher than 7 or 8..... My guess would be around 18 or so, but that's a WAG.


Dan

it is my understanding one must have arsenic for the water dropping to have effect... antimony hardens without waterdropping. , tin make it more fluid to fill molds and adds some hardness which softens with time , and lead .. well its soft . please correct me if im wrong

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

[GabbyM]

I run alloy similar to that, but oven heat treated and softer, in a 44 mag out to over 1,500 fps with gas checked bullets. As do others. In a 454 you should be able to run that bullet to about 36,000 p.s.i. Give or take. Even in a rifle you won’t have a velocity limitation due to your stated alloy.

I cast that same Lyman bullet from staright air cooled 2:6 alloy at around 15 to 16 BHN and we laod it full up in 454 Casull.

If you really have 96/2/1 your BHN is around 18. Depending upon several variables. should be plenty hard enough.

[evan price]

97/2/1 is 18 bhn???
92/6/2 is roughly 15-16 BHN air cooled and water quenches to about 20.

It's the gas check that is allowing you to use those bullets in the Casull- no burnt bases...Going much over 1200 fps will require good lube.

[R.M.]

Where can I find this? If it's at 10.7 ac, I should be ok water dropping these.

I thought it was a Sticky here, but don't see it. It's an Excel spreadsheet. Seems to work well for me. How accurate it is I have no idea, but from what I've done with it, it seems pretty close.
Do a search, and if you still can't find it, PM me, and I can send it to you in an e-mail.

[cbrick]

it is my understanding one must have arsenic for the water dropping to have effect... antimony hardens without waterdropping. , tin make it more fluid to fill molds and adds some hardness which softens with time , and lead .. well its soft . please correct me if im wrong. http://www.lasc.us/WiljenArsenic.htm

No, there must be antimony for any type of heat treating to work, either quenching from the mold or oven heat treating, the arsenic will greatly enhance the effect. You can HT without arsenic but not to the same degree as with it.

The tin reduces the surface tension (as long as the alloy temp is below 750 degrees) of the alloy flowing into the mold (the stream of alloy into the mold) allowing it to fill out the mold with much better detail.

Rick

[GabbyM]

97/2/1 is 18 bhn???
92/6/2 is roughly 15-16 BHN air cooled and water quenches to about 20.

It's the gas check that is allowing you to use those bullets in the Casull- no burnt bases...Going much over 1200 fps will require good lube.

He is water dropping the 92/2/1. I didn’t write that clearly.
Water dropped 2/6 should be much harder than 20 BHN. With variables they may not be. I chose to oven heat treat for greater consistency.

It’s hard to measure BHN on a heat treated bullet since they can be harder on the outside then graduate softer as the center of the bullet cools slower when they hit the water.
With a big 325 grain 45 caliber you’ll get a softer center. A 6mm bullet may be hard all the way through? I know with my 30 caliber rifle bullets from HT 50/50 if I don’t size them before HT I need to size them the same day I heat treat them or I can barely push them though the size if there is much to swag down. Sizing also work softens the bullet. On short fat pistol bullets sizing the 50/50 before HT is simple. However with long skinny rifle bullets sometimes will deform or bend when still soft. Most of my rifle bullets get very little sizing so it’s a non issue.

[fisheadgib]

He's water dropping, so it's quite a bit higher than 7 or 8..... My guess would be around 18 or so, but that's a WAG.


Dan


I generally don't use guesses wild or otherwise when I'm offering reloading advice. Water dropping (which I also do) is actually just case hardening the surface of the bullet and once you size the bullet, you eliminate some of the hardening on the sides of the bullet. I've played around with grinding bullets down a little at a time and checking to see how deep the hardening runs from the surface of a bullet and I've found that it is very inconsistent. If the newly cast bullet was the same temp when it hit the water every time, it would be more consistent but even a few seconds from pouring to dropping in the water can make a big difference on how deep the hardening goes. Some folks mentioned that they heat treat instead and this is actually a much better method if hardness is important. Heat treating after the bullet is sized will give a better uniform hardness over the entire bullet. Shooting too soft of a bullet in a high pressure chambering will appear to work fine for a long time but it WILL erode the top a little at a time. I learned this the hard way as after just a few hundred rounds through my 454casull I've noticed a slight groove in my top strap thats deep enough to hook my finger nail in. It's not going to fail suddenly but it will erode little by little.
Someone mentioned that bullets of the OP's hardness should be able to run at pressures in the 36,000 psi range so he should be ok. Thank you for making my point. The 454casull is rated to 65,000 psi and most of the "full house" loadings are in the mid to high 50,000psi range.

[bumpo628]

Where can I find this? If it's at 10.7 ac, I should be ok water dropping these.

Here you go:
http://castboolits.gunloads.com/showthread.php?t=105952
Get the latest version, which is currently 8/23/11.

The formula comes from Rotometals and R.M. is correct that it gives 10.7 as an estimate for that alloy. My calculator rounds it off to the nearest whole number to 11. If you're water dropping them then it could add 5 or 6 points to the hardness, so call it 16 or 17.

[Southpaw 72]

[QUOTE=fisheadgib;1388017
Someone mentioned that bullets of the OP's hardness should be able to run at pressures in the 36,000 psi range so he should be ok. Thank you for making my point. The 454casull is rated to 65,000 psi and most of the "full house" loadings are in the mid to high 50,000psi range.[/QUOTE]

I've looked at two sources of load data, hodgdon and lyman. Top loads for 325 gr gc runs from 35000-43000.

[GabbyM]

Shooting too soft of a bullet in a high pressure chambering will appear to work fine for a long time but it WILL erode the top a little at a time. I learned this the hard way as after just a few hundred rounds through my 454casull I've noticed a slight groove in my top strap thats deep enough to hook my finger nail in. It's not going to fail suddenly but it will erode little by little.


I don't understand the connection between bullet hardness and top strap erosion.

[cbrick]

It’s hard to measure BHN on a heat treated bullet since they can be harder on the outside then graduate softer as the center of the bullet cools slower when they hit the water.

With a big 325 grain 45 caliber you’ll get a softer center. A 6mm bullet may be hard all the way through?

Not true. Lead and lead alloys do not respond to HT as steel does. HT'd steel has a surface hardness, as the HT lead alloy ages the BHN will become pretty uniform throughout. Unless you have developed a method to alter metallurgy this is true of lead alloys.


Water dropping (which I also do) is actually just case hardening the surface of the bullet and once you size the bullet, you eliminate some of the hardening on the sides of the bullet. I've played around with grinding bullets down a little at a time and checking to see how deep the hardening runs from the surface of a bullet and I've found that it is very inconsistent.

Again, not true. You are placing lead and steel in the same category. Lead and steel DO NOT respond to HT the same, closer to opposites. STEEL will case harden. Terms such as case hardening do not apply to lead. True, you can remove some of the strength (hardness) from the driving bands by sizing.

Grinding, filing, sawing etc will not give you the info you are looking for. Steel (like brass) when worked will become brittle, lead when worked will become softer, you said so yourself when you mentioned sizing softening the driving bands. Working the lead (filing, grinding etc) to see how hard it is underneath will as you say, give very inconsistent results because it work softens the part being filed down.

The crystalline structure of a properly aged HT'd lead alloy will be pretty uniform throughout UNLESS you do something to physically alter it.

Rick

[R.M.]

cbrick, high carbon and tool steels get hardened all the way through. It's only the low carbon steels that get case-hardened.

[cbrick]

I don't understand the connection between bullet hardness and top strap erosion.

I don't either, something else at play here.

Too soft of an alloy at too fast of a velocity in a revolver will place extra and faster wear on the forcing cone. If the velocity is too fast for a soft bullet when the bullet strikes the forcing cone it will momentarily slow down the front driving band/nose, the rear of the bullet is still under full pressure in the cylinder throat in effect making the bullet bulge out a bit in the barrel/cylinder gap, the forcing cone must then act as a sizing die reducing the diameter and thus placing extra wear on the forcing cone.

I have many, many thousands of rounds through FA's in 454, 44, 41 and 357 and not a hint of top strap erosion in any of them.

Rick

[cbrick]

cbrick, high carbon and tool steels get hardened all the way through. It's only the low carbon steels that get case-hardened.

Ok but I think you got the point I was trying to make, at least I hope so.

Rick

[geargnasher]

Case hardening is the process of introducing carbon to the steel, commonly with a sacrificial substance like bone meal and/or leather. It only penetrates a few thousandths of the surface, making it wear-resistant but not strong throughout.

+1 to Rick's posts 12 and 18, he covers the facts pretty well.

Gear

[evan price]

I don't either, something else at play here.

Too soft of an alloy at too fast of a velocity in a revolver will place extra and faster wear on the forcing cone. If the velocity is too fast for a soft bullet when the bullet strikes the forcing cone it will momentarily slow down the front driving band/nose, the rear of the bullet is still under full pressure in the cylinder throat in effect making the bullet bulge out a bit in the barrel/cylinder gap, the forcing cone must then act as a sizing die reducing the diameter and thus placing extra wear on the forcing cone.

I have many, many thousands of rounds through FA's in 454, 44, 41 and 357 and not a hint of top strap erosion in any of them.

Rick

I think what is being implied here is that due to the volume of gas produced in the Casull, the bullet swell (which causes forcing cone wear) is also causing excess gas to exit via the cylinder gap and causing his topstrap erosion. Same problem with lightweight bullets at high velocity in 357 Magnums...forcing cone erosion and top strap gas cutting.

And I STILL do not see 97/2/1 alloy as getting 18+bhn even water dropped. 20:1 with no Sb is around 10 bhn or so; adding 2% Sb is going to double the BHN?
92/6/2 is 15 bhn AC and WC at about 20 bhn and that takes 6% Sb which is about all you need for most boolits.

[GabbyM]

Thanks for the information cbrick.

I’m still not confident in the BHN measurements on heat treated lead. I have the Saeco tester. For those who’ve never seam one. It’s a sharp pointed tapered steel pin that is slowly screwed into the test slug. Then you read a spring loaded scale for a Saeco number that loosely converts to BHN off an chart. Since HT lead work softens it always struck me the pin would be softening the lead as it penetrated. However so often what seams rational conjecture turns out to be in error. If I still worked in a shop I’d take in some slugs tested on the Saeco tester and run them over the BHN tester in the gage room for comparison. What I know is my fingernail test does not jive with my Saeco tester on heat treated bullets. A few years ago I saw BHN test tool comparison results on standard air cooled alloys.

Concerning hardness of heat treated 97/2/1 or 92/6/2. Results would depend greatly upon arsenic content. I’m not sure what the presence of trace levels of copper would do. I buy 92/6/2 foundry alloy regularly and never have received two loads identical in properties.

[cbrick]

A few years ago I saw BHN test tool comparison results on standard air cooled alloys.

Perhaps this is the comparison test you refer to.

http://www.lasc.us/Shay-BHN-Tester-Experiment.htm


Concerning hardness of heat treated 97/2/1 or 92/6/2. Results would depend greatly upon arsenic content.

Not so much the arsenic content (percentage), more that it is there. A very small percentage of As will have a dramatic effect on the amount of strengthening of a Pb/Sb alloy. About 1/4 - 1/2 of one percent is all it takes, adding more As will do nothing.


I’m not sure what the presence of trace levels of copper would do.

Almost all alloys used in bullet casting should be considered as scrap metal and WW is probably on the top of the list. Scrap alloys have many different elements considered by bullet casters as contaminents such as aluminum, copper, Cadmium etc. Many substances such as wax's and oil's will reduce tin back into the melt but will not, cannot remove any of the contaminents.

Flux with sawdust! Sawdust will not only reduce tin but it's also good at removing many contaminents. If your concerned about copper or other contaminents sawdust will go a long way in removing it.

Rick

[white eagle]

I'm using a 97/2/1 alloy water dropped in my 454. Good accurracy and no leading.:drinks: Any one care to guess what the hardness might be? How hard can I push it?

let me pose this does it make any difference
its nice to know but really your gun shoots good and there is no
leading two keys to the puzzle already solved
good job [smilie=w::awesome:

[Southpaw 72]

Flux with sawdust! Sawdust will not only reduce tin but it's also good at removing many contaminents. If your concerned about copper or other contaminents sawdust will go a long way in removing it.

Rick



Would cedar chips for pet bedding work as well. I have plenty of this on hand.

[Southpaw 72]

let me pose this does it make any difference
its nice to know but really your gun shoots good and there is no
leading two keys to the puzzle already solved
good job [smilie=w::awesome:

The load I used was a starting load. I was wondering how far I could push this alloy before I ran into problems, either with leading or at the forcing cone. I'm new to casting so I'll probably ask alot of seemingly dumb questions.:oops:

[badbob454]

cbrick i agree with all your statments you must understand lead alloys and their place in the whole picture , i have studied for years so i can cast well and have the correct alloy for the job

[badbob454]

Thanks for the information cbrick.

I’m still not confident in the BHN measurements on heat treated lead. I have the Saeco tester. For those who’ve never seam one. It’s a sharp pointed tapered steel pin that is slowly screwed into the test slug. Then you read a spring loaded scale for a Saeco number that loosely converts to BHN off an chart. Since HT lead work softens it always struck me the pin would be softening the lead as it penetrated. However so often what seams rational conjecture turns out to be in error. If I still worked in a shop I’d take in some slugs tested on the Saeco tester and run them over the BHN tester in the gage room for comparison. What I know is my fingernail test does not jive with my Saeco tester on heat treated bullets. A few years ago I saw BHN test tool comparison results on standard air cooled alloys.

Concerning hardness of heat treated 97/2/1 or 92/6/2. Results would depend greatly upon arsenic content. I’m not sure what the presence of trace levels of copper would do. I buy 92/6/2 foundry alloy regularly and never have received two loads identical in properties.
copper will harden in small quantitys with heat treating see my original post with the thread highlited Post no. 8

[badbob454]

Flux with sawdust! Sawdust will not only reduce tin but it's also good at removing many contaminents. If your concerned about copper or other contaminents sawdust will go a long way in removing it.

Rick



Would cedar chips for pet bedding work as well. I have plenty of this on hand.

yes its the carbon that is doing the job ..

[Matt_G]

Would cedar chips for pet bedding work as well. I have plenty of this on hand.

Yes, it should work just fine.