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brinell hardness - how much
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i wonder if someone might set me straight. i have been water hardening my bullets, made from wheel weights, and am getting hardness (measured on an LBT hardness tester) of usually around 15 or 16. i hear differing stories about leading and the cause. it seems to me that if the alloy is too hard, the bullet may want to slice rather than engrave when it initially contacts the riflings and thereby lead the chamber end of the barrel.

my own experience is with the wheel weights and BHN ~ 15 or 16 only. can some of you more experienced casters shed me some light here? if i don't water harden my bullets i imagine they will test around BHN 10 or so. would i be better off from a leading perspective if i go with a softer bullet than the BHN 15?

i ususally shoot 200 grain bullets in a 45 ACP around 850 fps. i am contemplating casting 230 grain bullets for 45 Colt at ~ 1100 fps and 454 Casull at ~ 1600 fps.
 
Posts: 466 | Location: Oklahoma | Registered: 20 December 2000Reply With Quote
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Bill, hardness is not the whole answer. Toughness is the sought after attribute. Add some tin to increase this parameter. It appears you have too much antimony for your application, and adding some tin will fix the boolit somewhat. Now, if you are still getting leading when water dropping, then don't water drop for the next test. Wait at least a week before shooting any new batch of boolits. They need to become more stable and uniform. If they still lead, then work on diameter, if that hasn't been done already. ... felix
 
Posts: 477 | Location: fort smith ar | Registered: 17 September 2002Reply With Quote
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......Bill, in your 45ACP your straight unquenched WW boolits shold be just great. Just as long as they're sized correctly and have a decent lube.

I'd also think they'd be fine in your 45 Colt. In my Vaquero I shoot WW equivelent alloy (12-14) bhn, but will admit to not shooting that fast. If the boolits are GC'd then your safe with that alloy even in the Casull.

I think the main problem with revolters, ah I mean revolvers, is the hoops the boolit may have to jump through before getting to the target. Funneling from the case through the throat and out the chamber mouth. Then leaping across the gap and into the forcing cone. Finally downbore and out.

It amazes me sometimes how well they CAN shoot :-). If any of the above is funky, then even a FLGC slug will have a hard time of it. Your Casull is too finely crafted to have issues, from what I've seen of them.

I wouldn't worry about the alloy being too hard to NOT smoothly engrave. If the bullet was brittle then there may be an issue. Like if you had an alloy with a very high antimony content. But if so, you'd have a heck of a time pouring good bullets.

I've fired WW like alloy from my wife's 38 Super using the Ly 147gr, (153gr) FNBB slug to 1250 fps. It produced target grade accuracy and no leading. Of course I have to brag on the pistol as it's been accurate with most anything.

So, to boil it down you should simply load up 25 unquenched with the load you want to use and try'em. The Casull at that 1600 fps WILL need hard bullets, or at least GC'd ones.

.........Buckshot
 
Posts: 119 | Location: Redlands, Calif | Registered: 21 August 2003Reply With Quote
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Bill.

I had leading problems when I started casting bullets for semiautomatic pistol.

Then, I had same doubts as you have now : relationships among speed vs. hardness vs. leading/accuracy during 300/400 rounds.

I found the answers to my questions in the following paper:
"A few Notes Regarding Cast Bullet Alloys" by Norm Johnson.
membres.lycos.fr/shooter/norm/castbull.htm
(without www).
This six pages paper explains , among other issues, relationship among speed/pressure/Brinell hardness, why sometimes leading problems can be eliminated by using softer bullet rather than harder ones.
You may also find there very professional transcriptions of The Fouling Shoot magazine, which support Mr. Jhonson recommendations.
The last but not the least important thing, under my point of view : when you get the most adequated hardness for your bullets,if you want to optimize them, the next step is to fit the bullet to the barrel by oversizing bullet diameter over barrell diameter.(this is fully explained in Lyman Handbooks).
If you are going to buy the sizing/lubing dies for the new calibers, it is not bad idea to slug the barrell first and buy the most adequated diameter for your revolvers.

Hope this helps

BA Shooter
 
Posts: 126 | Location: Buenos Aires, Argentine | Registered: 21 August 2003Reply With Quote
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My two cents...I remember when I use to shoot in the Tulsa indoor range and was buying their boolits which were 38 cal DEWC's. I was loading these over a very small amount of Bullseye in 38 casings. Velocity was very low. I got severe leading and it was only with their boolit, nobody elses. I called them and they were fully aware of the problem and corrected it...the problem was they put too much tin in. From what I understand tin doesn't have anything to do with harding the boolit alloy but only serves to let the molten alloy fill the mould out better. Like I've said before I've been lucky shooting cast boolit out of the many revolvers, rifles, and semi-autos that I have had or owned at one time or another. I've never ever had to scrub the hell out of the bore on any of them.

The one thing not mentioned here is maybe the gentleman that posted the original post might try some different lubes.

Joe
 
Posts: 2864 | Registered: 23 August 2003Reply With Quote
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Joe, you should never let tin exceed the antimony content, unless you have some arsenic included. Some arsenic. at least a hint of it, helps all boolit materials. The idea is to have tin completely surround all antimony on the molecular level, and that's all. Any more with arsenic creats a slippery bond with the lead molecules, thus allowing stripping. ... felix
 
Posts: 477 | Location: fort smith ar | Registered: 17 September 2002Reply With Quote
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without arsenic NOT with arsenic
 
Posts: 477 | Location: fort smith ar | Registered: 17 September 2002Reply With Quote
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I am using air cooled WW plus 2% tin with gas checks in rifles and get 2K plus velocity with zero leading. I use the same alloy in pistols and revolvers. In revolvers I can get 1,200 - 1,300 fps with no leading but over that in a revolver you will need either a gas check or a harder alloy such as No. 2. I am not a water drop fan, but is there is a place for it in revolvers, it would be in the 1,400 fps plus velocity range.
 
Posts: 263 | Location: Corpus Christi, Texas | Registered: 23 December 2002Reply With Quote
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No argument with anything posted herein. Dimensions, metallurgy, and lube qualities all figure into the equation, and some applications are kinda finicky about all three.

The 9mm and 40 S&W feature very fast twists that REQUIRE hard alloys and soft lubes to extract good behavior with cast bullets. The 9mm is almost always oversize, too--.357" is closer to what's real than the nominal .355" the grooves are supposed to be. The PPC types using the Beretta 9mm's for target work re-barrel to a 1-18" or 1-20" pitch and a .355" dimension. Properly fitted, these 9mm's are surprisingly accurate--same story with the 40 Short & Weak.

My 357's both have .3575" throats and .357" groove diameters, and they do nice things with .358" cast bullets. This subtle funnelling effect is about ideal in wheelguns. An older Colt Officer's Model Target (38 Special) I scrounged recently is even better--.3575" throats, .357" groove in the back end of the barrel and about .356" near the muzzle. Pythons also have this "choke" effect, and they drive tacks with lead bullets.
 
Posts: 299 | Location: Yucaipa CA | Registered: 21 December 2002Reply With Quote
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