Proper Bhn for .45 ACP?

[TimBoothe]

I was just wondering what the general consensus is on how soft of a bhn can be used for 45 acp without running into leading issues? I'm looking at around 882 fps maximum...how soft can I go?

I'm going to be using Ramshot Zip. I've done the calculation of dividing the pressure by 1422 to get a bhn and come up 12.6, but I'm sure that I've read posts on here somewhere where folks have used boolits softer than that. I'm in the process of trying to cook up the proper alloy and I'm about to pull my hair out.

See, I've got plenty of what I would call "soft" lead, it comes out to a bhn of 6.2(I've tried to water quench it and it still won't get harder, I assume from lack of tin). But I'm kind of limited on WW lead. I decided to try a 3-1 mix of soft-ww and after a little more than one week of curing time I'm getting a bhn of 7.8.

I'd love to be able to use as much of the soft as I can, but I've got a feeling that I will at least have to go 2-1 or maybe even 1-1 soft-ww.

What say all ya'll? (that's the plural of ya'll by the way)

TimBoothe

[454PB]

You need some antimony in the alloy for heat treating. 50/50 WW and pure lead should work. Personally, I just use straight WW alloy and no heat treating for .45 ACP. My WW alloy measures 12 BHN.

[TimBoothe]

Thanks 454. I'll look into adding antimony to my 3-1 alloy before I try a 2-1 mix.

TimBoothe

[jhalcott]

I use ww or Lyman#2 for the 45ACP. I am NOT sure but pure lead MIGHT not work well on the feed ramp. I guess a coat of LLA might even work in this situation.

[TimBoothe]

The only source of antimony that I have is some shot. I've got an older model Lee furnace, I think around 10pds. Any idea how much shot I should add?

TimBoothe

[HeavyMetal]

Careful when adding shot, it can contain arsenic, trace amounts(?) that can make the alloy brittle if you use to much.

First do you have clip on style WW? If so this is your souce for antimony. If not then I'd add about a half pound of shot to your 10 lb pot cast some samples and check BHN water drop will harden and will also allow you to handle the boolits faster for BHN testing.

Simple trail and error will get you to your target BHN.

12.5 BHN should be very do-able but I will suggest you write down your "formula" for repeatablity in the future.

[Shiloh]

I've been using range scrap and other scrounged/acquired lead supplies. It is pretty soft and there has been no leading in the 1911 or .38/357 to 775 fps. I have gone up to 840 with no leading. These have been LEE TL boolits with lube on the noses. I'll try others this spring.

My pistols don't seem to be picky. Others may.

Shiloh

[Kraschenbirn]

Like Jhalcott, for many years I've used either straight WW or Lyman #2 for my .45 ACPs...mostly depending upon which I had on hand at the time I was casting. "Hardball" loads with either...225 gr TC or 230 gr RN @ 825 fps...shoot quite well in all my Gov't Models.

Bill

[Scrounger]

The theory is that a "Bhn" (Brinell Hardness Number) is the strength to hold form under 1450 pounds of pressure. WheelWeights are about 10 or 11 BHN so they should stand up to 15,000 to 16,000 pounds pressure, which covers about 95% of .45 ACP loads. Another 'for instance' is Linotype which should be about 21 BHN, good for about 30,000 pounds pressure. This is theory, your results may vary.

[TimBoothe]

Thanks for the replies fellas. Heavy, all of the WW that I have is clip on. I'm thinking that one thing I haven't done yet is to take my 3-1 soft-WW mix and quench it. Like I said above, my soft lead didn't benefit at all from quenching and I'm assuming that this was from lack of antimony and tin. Now that I have at least some antimony from the WW in the 3-1...maybe quenching this mix will bump the hardness up from 7.8.

TimBoothe

[TimBoothe]

Oh I forgot to ask, how long after water dropping should you wait before you test the bhn? I know the proper time for air cooled is around 2 weeks, but what about water dropped?

Thanks fellas,
TimBoothe

[GSM]

Tim:

If you have some commercial "hard cast" bullets you don't like, these can be added to the soft lead to bring the hardness up as well.

[TimBoothe]

Scrounger.
See, this is where I'm getting confused. I've read on here where folks are pushing somewhat soft alloys up to some really fast speeds, not sure what kind of pressures that they have though.

The Ramshot load sheet info tells me that the Ramshot Zip Max Load Pressure is 18,600 - 19,200 for a 230 grain bullet. If I take 18,600 and divide that by 1422, it gives me a bhn of 13, 18,000/1422 would give me 12.6. Now that is with the "Max Load" which I will not be attempting. I wonder if there is a way to determine what the pressure is for a lighter load? All that they have listed is the max though...

I'm just wondering what would be the softest recommended bhn to try and use in my .45

Thanks fellas,
TimBoothe

[454PB]

Tim, your gun will answer all those questions. Theory never replaces actual performance.

Heat treated boolits tend to continue to harden over time. Two weeks is probably fine, the hardening process slows after that. I did some long term testing experimentation and found with my alloy and methods they reach maximum hardness at about 6 months, then begin to resoften at about a year. If you do water quenching from the mould, they need to be sized quickly. I size them the same day, but others have reported they can wait 24 hours or so. Two things happen if you wait too long: #1 they begin to harden and make sizing effort increase, #2 any hardening that has already occurred is removed by the sizing process.

[lawboy]

I regularly shoot many thousands of 45acp bullets at bhn 9-10 without any problems with leading. I use soft alox lubes. My load uses 4.0grs BE and gets to 900fps in a 6-inch longslide, 700fps in a 3-inch compact.

[Boerrancher]

Tim,

Just remember two things, when choosing an alloy. A 22 long rifle runs around 1200 fps and it is made out of pure lead. The second thing is the larger the bore diameter the greater the bearing surface so the faster you can push a boolit with out leading. If you are wanting less than 900 fps pure lead will work just fine. With the proper lube 1200 fps is easy in just about any 35 cal or larger.

Best wishes from the Boer Ranch,

Joe

[TimBoothe]

Lawboy, Boerrancher......THANK YOU!!! Thats what I was hoping for was to use this soft stuff up.

Thanks to all for the help and info,
TimBoothe