More casting questions

[AJC1]

1. How close are your bullets to the advertised weight on the mold. I know mine is off because my lead is soft and I hope to add some hardball soon. I'm dropping 242 after PC on a 230.
2. How much weight variation do you accept. I would guess 2-3 grains would be ok in a 250 class bullet. I hear of some long range black powder guys being very sensitive. I'm not there yet with a total of one casting session under my belt.
3.how long does it take to become proficient. I feel so far I have had some good luck. Made 150 good bullets in about 100 pours, first pours being to warm up the mould.

 

[reddog81]

It’s very rare for the bullet to match exactly. 10 grains off on a 230 grain mold isn’t uncommon.

I’ve only weighed bullets to see weight distribution 2 or 3 times. They were surprisingly close unless the bullet had an inclusion on the base. 2 or 3 grain variations for a 230 grain bullet would probably be on par with most commercial casters.

The first casting session is as much learning sessions as it is a casting session. After 3 or 4 times casting you should be able to get a good rhythm and start cranking about hundreds of bullets with ease. Learning the quirks of the pot, mold, lead pour all take practice.

 

[Ozonebob]

Hi AJC1,

As you have noticed, the weight of the bullet varies with the alloy. For 250 grain bullets, I have noticed a 2 - 4% variation in what the bullet is "supposed" to weigh and what I get. Many mold manufacturers will specify the alloy they used to set the weight. You can expect this amount of variation.

Bullets cast in the same session will vary in weight by around 1%, but there are lots of sources of variability here too. For example, the first acceptable bullets from a mold that's warming up can be several grains lighter than a fully warmed up mold, or bullets cast right after adding alloy to the pot, etc. Keep in mind that bullets with no visual defects can vary by 1-1.5%.

It sounds like you already have pretty good skills, because you have created a high percentage of "keepers" from your casting session. You can improve your skills by reading all you can about other peoples' experience and especially troubleshooting casting problems. Molds are like guns; each has its own personality and its own preferred casting technique. In this hobby, you never stop learning. I've been casting for 35 years and I am still learning.

Over time, you learn what to pay attention to, and what you can ignore. For example, save the bullets that have minor defects. Load them and shoot them the same as you would your perfect bullets. If they group the same, you can ignore those minor defects.

Welcome to a great hobby.

Ozonebob

 

[.38 Special]

I actually don't care, at least with handgun bullets. My newest "true Keith" mold for the .44 drops bullets at precisely the diameter I want. I haven't actually weighed any of them, though.

I do weigh bullets for my Gibbs long range rifle. I've read that one should hold to +/- one grain, with a 535 grain bullet. I am keeping them to +/- four tenths, because I'm just that good. If only I knew how to shoot a rifle, that might actually matter.

 

[.38 Special]

Seriously, with regard to #3, I have been doing this for about 30 years and still manage to feel like a complete beginner, at least on occasion. For the most part, though, I go into a casting session expecting near-perfection, and am surprised when it doesn't happen.

If I could go back in time to give my younger self a pep talk, it would go something like

1) Use a known alloy. A lot of the wheel weight/range scrap/this-friend-of-mine-has-this-stuff stuff worked great. Some of it didn't, and I blamed myself. Now that I have been at it for a while, I have the confidence to understand that some of the junk that ended up in my pot simply could not be made into good bullets.

2) Get a thermometer. Seriously. If you are guessing at your temperature, you are guessing at everything. Spend the twenty bucks.

3) Now that you have a thermometer, don't be afraid of heat. Run the pot at 800 to 850 degrees. The worst possible outcome is frosted bullets, which shoot just fine. I'm not actually sure why people try to run the pot as cool as possible. I like shiny bullets as much as the next guy, but alloy at 650 or 700 degrees is just a big old headache.

4) Pre-heat the mold, and soot it. I hate pouring bad bullet after bad bullet to heat the mold. For years I used a heat gun to warm up the mold while the alloy was melting. That works, more or less, as does a hot plate. Eventually I just started dipping the lower front edge of the mold into the molten lead for a couple of minutes. Apparently this violates the warranty on some molds, and it definitely causes some pearl-clutching in certain quarters, but I have been doing it with iron, brass, and aluminum molds for a couple of decades now and have not damaged any of them. After you've got the mold good and hot, use a butane lighter to give a decent coat of soot to the cavities, then start your pours, making sure to leave a good sprue puddle over each cavity.

With all of the above, my rejection rate is in the neighborhood of one percent - and I am picky. There was a time when I would have accepted 100 good bullets for 150 pours, but today I would immediately find that problem and fix it.

Please keep us posted on your progress. With the benefit of all the knowledgeable members here, I am sure you will master this business in no time!

<Edit> Sober, I note that I misread the OP's sentence regarding the number of bullets/pours. So while my point still stands, I acknowledge that it doesn't have anything to do with what the OP wrote.

 

[243winxb]

advertised weight

Bullet molds are regulated for a certain alloy. Lee 10-1 lead/tin. Lyman #2. A higher percent of pure, more weight.

weight variation

Out of a 10 lb pot i take 3 samples of 4 bullets each as they drop from the mold. Start, middle, end. Weight & diameter are checks as soon as the first 4 cool.
Antimony makes bullets lighter, harder & larger in diameter. Tin, not as much.
The 3 Saeco moulds diameters are larger then i like. (Sizing down more then.003" is not good for accuracy. Lyman) I agree.
The bottom right info, Lyman 45 acp mould just just barely makes diameter of .452"

Moulds- Saeco 382/158gr lswc & 441/240gr. Lyman 452630/200gr bb.

Technique on the Lyman 45acp cast, not as good as i like.

 

[243winxb]

This mornings shooting results.

 

[WrongHanded]

This mornings shooting results.
View attachment 922067 View attachment 922068

That first target looks like a winner to me!

 

[AJC1]

I actually don't care, at least with handgun bullets. My newest "true Keith" mold for the .44 drops bullets at precisely the diameter I want. I haven't actually weighed any of them, though.

I do weigh bullets for my Gibbs long range rifle. I've read that one should hold to +/- one grain, with a 535 grain bullet. I am keeping them to +/- four tenths, because I'm just that good. If only I knew how to shoot a rifle, that might actually matter.

You sound to be a lot like those long range BP guys. Hoping my skill gets there...

If you dont weigh your casts how do you screen for included bullets?

 

[tightgroup tiger]

You shouldn't get inclusions if you alloy is clean, your pot is clean, your alloy is up to temp and you have enough tin in your alloy to fill out the mold. If you accidentally put zinc or pewter in your alloy then you will have problems with inclusions.
Normally, if you meet all of the above, you should have happy casting ahead of you. As far as tearing out the base of the bullet, you have to play with how long you wait before cutting the sprew off.

I'm a lot like 38 special, I worry about my alloy up front when I'm pouring ingots, and I seldom have problems casting good bullets. My bullets all weigh light because I have more antimony in my alloy than I need for low pressure loads, but they still seem to be really accurate and minimal leading, so I don't mess with that.

I drop my alloy on a towel and let them air cool so they don't get any harder than they already are.

A lot of this is trial and error, just like finding out what load you gun likes or doesn't like.
My Sp101 likes this load and my bullet alloy, standing, shooting off hand at 25 yards with a 3" barrel. I'm no bullseye shooter but I will take this any day of the week. The range I shot this at didn't allow anyone to sit or kneel to shoot. I've since went to a 90 gr SWC and it shoots just as good.

 

[.38 Special]

You sound to be a lot like those long range BP guys. Hoping my skill gets there...

If you dont weigh your casts how do you screen for included bullets?

Well, those long range BP guys can really shoot. I'm nearly useless with a rifle!

As for inclusions, Mr. Tiger gave a pretty complete answer above. I find that with foundry metal, inclusions almost don't exist. Wheelweights are a different story. I tend to cast with WW when I need bullets for speed work at close range, and foundry metal for more demanding pursuits.

 

[BWS]

If I was starting out again would;

#1 Take notes on each mould. Once you get a few/bunch,it's tough to remember the little nuances it seems each one has. Two moulds from the same co. can be as different as night N day. Not to mention moulds from different manufacturers.

#2 Make a mould oven. Cheapy single burner electric job. Then a metal coffee can that's a "shorty".... pic below. It accommodates two moulds but it's mainly just for one. The idea is obviously to preheat but is the bees knees when you want to run two moulds. Lets you run a mould in there and if the one you're using gets a little hot,you already have the backup. It also works great for new moulds to run a few heat cycles through.

#3 Digital thermometer. I cast for 40 years before getting ANY kind of thermometer,and did quite well. But as in #1,each mould has it's happy zone,keeping notes and a recorded temp.... you'll save some time.

#4 Don't be too reliant on data from other casters. Yes,listen,learn,and ask questions but there's nothing better than self actualization. Make some mistakes,it's OK. One instance is the moulds themselves. Just because someone got a crummy XYZ brand doesn't mean that much because again,each mould..... and EACH rig is a match upon themselves.

Gotta go take a pic of the mould oven,will edit. Sliding door is pretty trick. There's a 1/4" round steel plate that sits on top of burner element. Also cut another one to fit on top(this pic was before the 2nd plate was added).

 

[BWS]

Here's one showing the sliding door and the plate.

 

[Texas10mm]

You shouldn't get inclusions if you alloy is clean, your pot is clean, your alloy is up to temp and you have enough tin in your alloy to fill out the mold. If you accidentally put zinc or pewter in your alloy then you will have problems with inclusions.
Normally, if you meet all of the above, you should have happy casting ahead of you. As far as tearing out the base of the bullet, you have to play with how long you wait before cutting the sprew off.

Pewter is my source of tin. I've never had a problem, nor should pewter cause a problem.

 

[highlander 5]

Last batch I cast using an NOE mold 6.5 cal block says 126gr with a gc they came in at 124-126 gr . On average my cast bullet weight varies 2-3%. Sized .266.