Hardness for .357 Magnum Lead Boolits

[CajunRebel]

I have a Dan Wesson .357Mag, 8" Vented heavy barrel, loading Lyman 358156 mould with gas checks, IMR4227, 15.3grs. Using shooting range gathered lead/jacketed bullet meltdowns, not experiencing any leading. Until my Lee Lead tester comes in, decided to have friend test a few boolits for me. He said it was roughly 10.7 Brinnel, 13288 chamber pressure. I guess I'm exceeding the specs. What hardness should be my mix?

[lead Foot]

I use Water dropped wheel wights in my Dan.Works OK for me I use the RCBS 35- 200 fn @ 1150fps for silhouettes.
Leadfoot;

[HeavyMetal]

The gas checks are helping greatly in keeping you from leading with this alloy.

Bottom line: if it ain't broke don't fix it!

However you did not say how many rounds you fired or intend to fire with this load. So if you blasted off 3 or 4 hundred and had no leading I'd leave this load alone. If you have only fired a handful then more shooting is needed before you decide this load is not leading.

If you plan to buy or cast a plain base boolit then you may need to change your alloy.

Things to do with a plain base mold.

1 size to cylinder mouth not the bore. If no leading your good.

2 If you encounter leading with you current alloy try another lube. If you can dertermine where the leading is you may also get a clue as to it's cause. For example if your boolits are the correct size and you have leading in the forcing cone or just ahead of it Harden your alloy.

If the leading is "later" in the barrel, say up around the muzzle, a lube change is in order what your using is failing before the boolit exits the bore.

3 if you have leading the length of the barrel, forcing cone to muzzle, then it's both lube and alloy.

The Lee hardness tester will have a chart of pressure / BHN compatible numbers for you to go by select / make an alloy that works with the pressure of the load your making.

4 Do Not make the mistake of thinking that Tin is an alloy hardner! It is not! Tin increase's the alloy's ability to "flow" and helps fill out. The metal you need to harden is antimony. This can be found in clip on ww metal, hardened shot and, of course, Type metals used in the print industry. Be careful when buying WW metal particularly off the web many will tell you it's clip on but they will melt all WW into one batch as they get it. If I buy WW I want it in it's original form so I know what I'm buying!

Hope this helps.

[fredj338]

I have no issues shooting 50/50 ww lead mix to 1200fps+. Porper lube & sizing & a smooth barrel are more important than BHN being 10 or 12.

[MakeMineA10mm]

Heavy Metal has already hit a LOT of good points. I'll just add some more, or emphasize what he's already said.

First off, I compliment you on your choice of 4227. This powder is superior, IMO, for cast boolits, compared to the similar ball powders, like H110 or W296. Something in the way the stick powder burns that is better for cast boolits. In addition, the slow pressure rise with 4227 is more gentle to your boolit than a faster pressure-rise powder. These things are helping you.

Second, I'm not 100% in the camp of those who equate a certain hardness to a certain limit of pressure. I agree with them that certain hardness equates to a certain level of pressure, I feel it has more to do with what kind of deformation of the boolit it is doing. Now, putting a GC on the boolit, making sure the boolit fits the chamber throats, and having a good forcing cone in the back of the barrel, all make me worry a lot less about whether I'm exceeding the "pressure limit" of my alloy.

In actuallity, I think getting up to that pressure is important, because you finally reached a level where the lube groove is pumping the lube out against the bore due to base/internal deformation of the boolit. That is making your lube work better. Any problem you may be encountering with lead could be because the 156 boolit (as much as I love it) has a round-bottomed and small lube groove. These are slightly troublesome. If I'm loading this boolit in 357 cases and with heavy loads, I re-lube them to get lube into both crimp grooves as well as the lube groove. I also jumped on the group-buy here for a plain-base version of the 156 that had a bigger, square-bottomed lube groove.

[runfiverun]

who cares how hard it is?
i shoot the ingots under my bench melted into 44 mag sized boolits to 1600 fps
with no gas check.
yeah i got a hardness tester and i can manipulate my alloy with either softer or harder alloys.
but i just heat the pot and keep on making them, the rifle and revolver keps on shooting them.
an 11 is a nice hardness by the way.
my secret alloy is ww's i got and 20% softer lead i got somewhere else.
same mixture in the 25-20, 30 carbine,357 ,45 acp, 45 colt too.
if i need harder i put them in water from the mold.

[Blammer]

I took some of my ww air cooled GC'd 180gr 358 cal boolits and shot them out of my 35 whelen at 2400 fps, no leading.

Personally, I think AC ww's are very good.

[Harry O]

The pressure vs hardness formula is only supposed to be for plain base bullets. Since you are using a gascheck, forget the formula.

I originally tried the 358156 with a soft cast mix (about Bhn 6 to 7) like some people have suggested. The powder was 13.5gr of 2400. I did not get leading (the GC did its job), but I also did not get any accuracy. I tried two harder mixes. The first one was Bhn 10-12. It was accurate and did not lead. Then I tried Bhn 16-18. The accuracy was equal to the Bhn 10-12 ones and also did not lead.

Since I am cheap, I have mixed up Bhn 10-12 for this ever since then and have not had any problems with it in by Ruger GP-100 or my S&W 686. It works for me.

[45r]

I shoot air cooled WW rcbs 158GC boolits and no leading.CCI 200's and 14.0 grains 2400.Put a few cylinder full into a two inch group at 30 yards today,they usually go close to an inch but the sun was too bright to get a good sight picture with my old long barrel model 27.They shoot a little better than my 358156 lymans,I think the stronger drive band helps.I lube and put the gas checks on with a .360 die in my lubrisizer and run them up through a lee polished out to .359.

[Bret4207]

If it works, don't mess with it. This isn't science exactly, more of an art. What you have works so don't worry about the details. Don't worry about supposed formulas and hardness and whatnot. Just be happy that what you have works and enjoy it.

BTW- You made an excellent choice in boolits! The 358156 is a wonderful design.

[HangFireW8]

4 Do Not make the mistake of thinking that Tin is an alloy hardner! It is not! Tin increase's the alloy's ability to "flow" and helps fill out. The metal you need to harden is antimony.

I cast up some 16:1 lead/tin boolits using BHN6 sheet lead and 60/40 solder, and they came out to a BHN of 10.5, which jives pretty well with the classical rating of BHN11.

So, the facts r'a'gin u.

If you want to complain about the cost of tin, that is fine, but tin is a hardener, like it or not, and wheel weights can't be had in these parts for love or money, but solder is just waste given away.

-HF

[Aegis]

Make sure you check your ports after each time your done shooting. I have a taurus 608 that I didn't clean the ports on for 1500 rounds. :groner: I had to use a small drill bit and a pick to clean them out.

[MakeMineA10mm]

There is a very long and good thread (stickied, I believe) around here talking about alloys and hardness. It cites and expands upon some very scientific work that is a chapter in the Lyman Cast Bullet Handbook and (same article) in the RCBS handbook. This article is about tertiary alloys (composed of three major components - lead-tin-antimony). This work points out that in tertiary alloys, tin should always be in an equal or lower percentage to the antimony, or you have mixture problems (lumpiness) as well as the fact that the tin and antimony combine to form a compound that provides much of the hardening in a tertiary alloy. The author of the thread here at CB explains that you don't need any more than 2-3% of both Tin & Antimony in your mix to make some really danged hard boolits...

There's also some information in the Handbook for Commercial Bullet Casters, I believe by Paul Moore (I'll have to go look for my copy to verify the author), but he is a metals expert (I believe chemist) who worked for a big foundry making commercial bullet metal, and he worked on the side with Magma Engineering. He has a chapter on alloys, and he points out that Tin IS a hardener, UP TO A CERTAIN level. Then, it's hardening quality falls RAPIDLY compared to how much of it you have to put into your alloy. This appears to be true for Binary alloys (made up of only tin & lead) as well.

Sorry, didn't want to side-track this thread, but thought this should be pointed out considering the discussion of alloy hardness and Tin above...