Bullets that softened

[Frank]

I have some cast bullets from a reputable co. that claims the bullets are BH 22. When I got them, I checked them with my Lee tester and it verified they were 22. But after a year and a half, the bullets are now BH 16. What happened? Too much tin? I don't mind that they got soft, just wondered what was the cause. Obviously they know what they are doing.

[lwknight]

I bet they have a high tin content. They could have been quenched #2 or something like that.

[Frank]

This is how they shot at 50 yds out of a revolver. The flier was too much bag fluff, it made the barrel not rise.
http://castboolits.gunloads.com/picture.php?albumid=123&pictureid=2782

[bhn22]

Cast bullets lose hardness over time. 6 bhn seems a bit much to me for one year, but whatever...

[runfiverun]

cast boolits normalize and stay at thier alloys hardness for a really long time [not sure how long iv'e only had a tester for about 15 years now]
sounds like you got an estimated bhn and tested it at something else.

[Shiloh]

cast boolits normalize and stay at thier alloys hardness for a really long time [not sure how long iv'e only had a tester for about 15 years now]
sounds like you got an estimated bhn and tested it at something else.

No way to know for sure, but I subscribe to this as well. Doesn't seem to be as issue as far as accuracy is concerned.

Shiloh

[Frank]

See, so even the companies make errors. The bigger the batch, the larger the error. :bigsmyl2:

[runfiverun]

since most company's use terracorp magnum alloy [bhn 16] which is 2% tin and 6% antimony.
thats most likely what they really were/are.
unless they used lino-type [22 bhn] and charged accordingly, they were using the hardcast ploy.
for some reason most reloaders want a bhn of about 6,000 even though copper jacketed is only 50 or so.
it took me forever to convince my customers that they didn't really need anything harder than 12 bhn, except for certain applications, and that fit was far more important.
so. they,,, ummm. estimate. since they can somehow harden thier lead by casting it, it has to be close to 22 or sumthin.
the hardcast thing kinda come about when swaging 5% antimonial lead produced a bhn of like 6-8 but casting that same alloy with tin made 15-16.
anyways, i am sure marketing had nothing to do with it.

:lol:

[lwknight]

Maybe they cast them into water and samled the ones that cast in cold water before the water got hot.
More likely that they just never counted on someone actually doing a test on them.

[Bret4207]

Could be that Lee tester too, a bit of rather difficult kit to use consistently from what I've seen.

[44man]

For what I shoot, air cooled WW boolits are not as accurate unless they have a gas check. I water drop all of mine. Now I keep loaded rounds and boolits around for a LONG time if I don't need them for something. They do soften but seem to shoot the same for me.
I have often wondered if BHN tells anything about grain structure formed when hardened and if time softening affects the structure. It seems it takes heat to change the structure, so does that have a different affect?
We need someone that can actually inspect the grain structures to see if there is a difference.
I use the LBT BHN tester and I get different readings from boolit to boolit and even on other spots of the same boolit. I have just never worried about it.
I would hate to measure a dimple! :drinks:

[qajaq59]

Well, it sure looks like they go where you want them to go. And that's all I ever ask of mine.

[runfiverun]

time softening affects grain structure.
that would be antimonial migration.
that'd be the best explanation for softening of waterdropped alloys.

[1Shirt]

I use a Cabin Tree tester, and have done a lot of comparisons on blts cast and water dropped(I water drop all of mine for convenience). Have some that I have tested after up to 5 years, and never found more than a 2-3 bh drop in that time frame. Think however that a lot depends on how you use the tester for comparisons.
1Shirt!:coffee:

[mpmarty]

I bought a LEE hardness tester. Used it quite a bit at first. Now it just sits on the shelf. Too much trouble and I really don't give a darn what the BHN is as long as they go where they're aimed and don't leave a bunch of lead in the barrel.

[btroj]

I'm with 44 man. I water drop everything. And mine may sit for years before they are shot. So I shoot them.
I don't get that wrapped up in hardness. If they work that is all I care. And so far, they work.

Brad

[Frank]

I try to maintain a level of consistency in what I'm doing. And it's standard procedure for me to check BH. I use the Lee tester. It gives quick, accurate results. I check a boolit at the end of the day after a cast. Then I check it again in 24 hrs. It usually jumps a few in one day. I know it also goes up a few in a few weeks, but I don't check it again. For example, I was wanting to cast some HP's for my 45-70. I wanted a BH of about 18. So I went with 50/50, added a 1/4 cup of mag shot and WD. I wanted to see how they came out. I don't "file a flat" on a boolit. I just take a flat piece of steel and lay it on the ram. Then put the boolit on the flat and measure the top of the boolit. It's very easy, very accurate and gives me the info I want. I can check them again and see what they are doing. It takes me 2 minutes to set-up and complete a hardness check.

[44man]

50-50 does not need the mag shot. But it might need oven hardened over water dropping. But either way, I found they NEED a gas check to arrest skid with my velocities. This mix might soften faster with time, I don't know. It is great for a flat nose but for a hollow point I want to try 75 WW-25 pure. That 50-50 hollow point will sure mess up meat. Don't hit a shoulder!

[Frank]

Thanks. Actually, I'm lucky, I had some alloy already in the pot. But you are right. 75/25 was the correct mixture.

[firefly1957]

Have any of you ever checked common temperature range on bullet hardness?
for instance checked the same alloy at say 0,30,50, and 100 degrees to see if it makes a difference.

[Baryngyl]

When they left the factory the very well could have been 22 BHN as you also said your reading was.
According to RCBS cast bullet manual #1, what happens is they get cast and are a certain hardness, but then they get sized which causes them to lose hardness after they sit for a while.

According to RCBS cast bullet manual #1, page 32, it says
Sizing is an important function to bullet casting. In addition to reducing runout, it allows bullets to be adjusted to differing chamber dimensions, within reasonable limits, However, it also introduces a problem where strength is concerned. Sizing , even a little bit, will cause any portion of the bullet which is worked to soften. The total loss in strength will vary somewhere between 25% and 75% depending on the bullets age, hardness and alloy content.


Michael Grace

[Frank]

Baryngyl "According to RCBS cast bullet manual #1, what happens is they get cast and are a certain hardness, but then they get sized which causes them to lose hardness after they sit for a while."

Evidence suggests sizing has no effect on boolit performance. Besides, I don't take measurements of the sides. I measure the nose.