Cast bullets vary in weight

[chadschroeder]

Hey everyone! I know that this has probably been asked before but does anyone have suggestions on why my
Lee 158-125FN (38spl) mold is casting at 124 to 130 Grains? Most of the bullets are coming out at 128g. This is unsized and unlubed. Straight from the Mold (cooled) to the scale.

I am brand new to casting. I just picked up the Lyman Big dipper starter kit. The Lead i was able to gather up is about 2lbs of Xray film thingys from my dentist. (i know thats pure lead) I have Wheel Weights and the vast majority is Range Scrap.

Now tonight i cast only wheel weights and i was getting 128g. last weekend i was casting using the Dental lead with Range Scrap. I was consistently getting 127g. During that casting session i tried adding some 60/40 solder to my mix. Same results. So either i didn't have enough tin or i just wasted $10 on solder. LOL i think its the later.

I know that there may be a tolerance of a couple of grains, but most places i read they are closer to what the mold is rated for. Tonight i even had one 124g and then 130g.

I haven't shot anything yet. Places i am reading say shoot them, see how they work. I am just trying to make sure that they are ok to shoot so i don't end up with out a gun or worse...

Also, i am actually quite proud of my self because most of the bullets are coming out looking really nice. I do get a few with wrinkles but most of them are looking perfect. (except the weight)

Well, Thanks in advanced for any tips for a worried noob.

[mroliver77]

Technique can make this much difference. It is important to make each pour as uniform as possible. If I am tired or hurrying I dont pay as close attention to rhythm or closing the mold right and get variations like this. I like to let my pot heat up for at least 1/2 hour or more to stabilize AND I preheat my molds. Adding metal to the pot whil4e casting is a no no in my opinion if you want consistant results.
So get a good system and stick to it. Everything ready and handy.
J

Oh and that litle variation will not make them unsafe at all. In a 38 you will see no difference in accuracy at least at my skill level at handgun shooting.
Jay

[chadschroeder]

yah i have read that technique goes a long way. So i am guilty... left over sprue off the sprue plate i have put that back into the mix after about 25ish bullets... I'll stop doing that LOL But still, before i did that i was still getting 128g. I guess i just need to practice. As far as preheating the mold and the dipper i figured that out with the dipper because if you put a cold dipper into the mix it hardens to the dipper. Its actually sorta neat. LOL

[chadschroeder]

Oh and that litle variation will not make them unsafe at all. In a 38 you will see no difference in accuracy at least at my skill level at handgun shooting.
Jay

So anywhere from 124g to 130g with a low power load like my 38 should be safe?

[mroliver77]

Yes no problem.
I am not sure I completely understood your question but I believe you were asking also about your different alloys weighing different too? As the components are of different weights an alloy with different proportions will result in a boolit heavier or lighter than listed for the mold. The makers regulate with THEIR alloy. So the listed weight is a reference # only for us lead scroungers.

[chadschroeder]

Yes no problem.
I am not sure I completely understood your question but I believe you were asking also about your different alloys weighing different too? As the components are of different weights an alloy with different proportions will result in a boolit heavier or lighter than listed for the mold. The makers regulate with THEIR alloy. So the listed weight is a reference # only for us lead scroungers.

so basically if i used say a 10-1 like it says in the lyman book thats how i'd get a more consistent weight for the die. Thats what i was thinking, but being new i wanted to ask some pros!
Also like on other threads, i find most people aren't even concerned with the weight unless they are having accuracy issues.

I do appreciate your replies and your help. I am excited about learning a new skill and having fun shooting something i've made.

[MtGun44]

Not just safe, but pretty standard. Don't sweat it. Make sure you are
fully closing the mold each cast, keep alloy consistent and that variation
should go down some.

Not really important, tho, for normal pistol ammo.

Bill

[gmsharps]

The more expierience you get the more consistant you will be. Watch the bases to see if they are flat or round. That can make for a fair amount of weight change. Try ladeling and that might may it more consistant also. It's mainly in the technique reguarding on how you do it.

gmsharps

[Mk42gunner]

While I don't sweat a variation of one or two grains, I think a six grain spread is a bit large. As others have said, with more experience the variation will go down.

Which Lee mold do you have, the two or six cavity? I can definitely see someone that has never used a six cavity mold before having that much difference, just by the way you hold the handles.

Are your boolits all round? Or are the heavy ones oblong because of not completely closing the mold?

If you are using a six cavity, do not hold the sprue plate handle while filling the mold; it will cause problems.

My recommendation is to pick one alloy and learn how to cast it before trying others. The neat thing about casting boolits is that you can have as many do overs as you want. Take an hour or so and cast until you find your rhythm, the boolits will more than likely weigh within a grain of each other then.

Aluminum molds like to be run hot, don't inspect the boolits after every drop, that just gives the mold a chance to cool down. Cast a fairly large pile then take a break and measure them with a micrometer to ensure roundness and weigh a few, you don't have to weigh each one, but enough to get an idea how consistent you are becoming.

Oh yeah, with wheel weights, I would expect a nominal 125 grain Lee mold to drop somewhere around 127-128 grains.

Good luck,

Robert

[Lizard333]

Good advice here. Can't help you there. But treating dental foils as "pure" might lead to issues. Mine are teasing around 8bhn with a cabin tree tester. I shoot these as is with 2% tin for my 45's.

[L Ross]

chad, if you are using enough expensive solder to raise your alloy to 10 to 1 for handgun bullets you are spending money unnecessarily. As Lizard333 mentioned 2% is adequate. One little trick I have found to help reduce weight variation is to tap the handle jaws shut, (don't hit the blocks themselves), with my casting mallet when I close the mould. Just a little tap to insure the mould is closed uniformly each time.

Duke

[44man]

Small variations of mold heat will change weight. Hotter makes a smaller boolit and colder makes larger. I never weigh any boolit, if it looks good it will shoot good, never seen a difference.
Now if I was shooting very small boolits for accuracy or distance I would weigh and sort.
Just load by what the mold weight says the boolit is supposed to be.
Looking to make the mold cast the marked weight is like looking for the velocity the book says, useless make work.
There are many of us here that shoot the smallest revolver groups on earth and I bet almost none of the boolits ever see a scale.

[JSH]

I would say adding the spruces back and not letting the pot set and come back up to temp is the major issue.
When ever I add back to my pot I let it set for quite a while. I lose some heat in my molds but I do set them on an old electric skillet. I always figure my first half dozen drops are culls and just drop them in the sprue bucket. Then I run as fast as the sprue setting will let me.
Jeff

[mroliver77]

One other thing comes to mind. I SMELT my alloy in larger batches. I use a pot capable of 100 lbs at a time. I use a cut off freon tank and a gas burner to heat it. Muffin tins for ingot molds.
If it were me I would mix the WW and range scrap 50/50 and add 1-2% tin and cast into ingots then use this as your alloy for the 38. Like has been said cast for the experience for a while.

[chadschroeder]

chad, if you are using enough expensive solder to raise your alloy to 10 to 1 for handgun bullets you are spending money unnecessarily. As Lizard333 mentioned 2% is adequate. One little trick I have found to help reduce weight variation is to tap the handle jaws shut, (don't hit the blocks themselves), with my casting mallet when I close the mould. Just a little tap to insure the mould is closed uniformly each time.

Duke

No!! I only did that as an experiement to see if it would thin or lighten the mix.

My bullets are coming out pretty desent and uniform. I havn't see an oblong one and I am sure that I am getting the mold closed all the way.
I will try to get the mold hotter. I have been letting it sit on top of the furnace while the lead is heating up. Btw it is a 2 cavity mold. They have been coming out round and look nice.

Hopefully I replied to everyone's comments or answered any questions. Thank you all for your tips and responses.

From here I think I need shoot and see how they react and maybe get some pure tin bars. Also I am gonna stop putting sprue back in and also try to keep my mold hotter.
Also gonna form the habit of tapping the handle and make sure it's uniform.

Thank you again. Great community of shooters here. You all made me feel encouraged and welcomed.

[JSH]

This is a do as I say not as I do or have done lol.
Watch how many things you change up at a time. If you change to many to quick and fix it, you may bypass the whole actual fix. If you follow me? One thing at a time so to speak.
I keep notes too. So much so that I keep notes on certain molds and their little quirks.
This is a good bunch here. They helped me get started and turned me into the monster I am.
Jeff

[gefiltephish]

Try marking them as they come out of the mold, with regards to which cavity they're from. Then weigh them and see if there is a consistent difference in weights from one cav to the other(s).

[fredj338]

I have very few molds that actually cast to the weight on the mold. My Lee 228gr RN is one. Most will be heavier, as I use more lead than tin. What I look for is consistent weights within the alloy I am using. A variation of 5-6gr for a 125gr ish bullet is quite a lot of variation. My larger 44 & 45 caliber bullets don't vary that much. I rarely weigh them, but when I do a spot check, they are all within +/- 3gr. I only weigh hunting bullets or bullets used for longer ranges, like my 45-70. Variation of more than 3gr can mean internal voids, not good for accuracy.

[chadschroeder]

Wow sounds like i have a lot to learn! good thing i have this forum so i can keep referring back to you all LOL. You all have given me great suggestions. I think JSH has a point though. There are some smaller things i can change right away but other things i should be more aware of while i am just switching things up to quickly. That way i don't over look the fix or create a new problem.

[MT Gianni]

I use a thermometer along with my lee pot. Full 9 might be 690 F while 1/3 empty it might be 775F. 1/3 full it might push 850 F. I adjust my dial, not a thermostat, to match a near temp on my thermometer. Why don't you mike your heavies and lights and see if they are wider or longer? Too long might indicate sprue issues and too wide closing techniques.

[leadman]

You could have fill-out issues also. Measure some of your light versus some of your heavy boolits to see if there is a difference in dimensions.
I recently bought 4 new style 2 cavity molds and 3 of them had sprue plate pivot bolts that would not stay tight, or had a shoulder that was tooo short so if the bolt was tight the plate would not move. This causes a variation in height, which also varies the weight.
Inspect the mating surfaces of the mold for specks of lead stuck to the faces. I use a push pin to pop these loose.

[Pakprotector]

hey-Hey!!!,
Numbers will go a long way to providing an answer. Getting good ones will require the consistnecy the others have mentioned...I am planning to examine the mass distribution as I learn this art. For a given batch of boolits( with as close as I can come to the same alloy ), look at things like standard deviation...as I see large numbers, I will be pretty sure I am not doing it right. As I write this it looks a bit like chicken v. egg; am I getting big SD because I am doing something wrong, or am I getting big SD because there is something I don't see?
cheers,
Douglas

[Boyscout]

I weigh anything that I plan on shooting out to 50yds or more. +/- 1% the average of the batch. On one hundred bullets I might end up scrapping 6 or 7. I weigh them and line them up by weight, take the average and remelt whatever falls outside my acceptable range.

[NSP64]

Welcome chadschroeder,
If your not casting for long range rifle, weighing is a waste of time. Load them and shoot them.

[Pilgrim]

Just to throw a monkey wrench in all of the good advice you've gotten....I put my sprues back in the pot as I go. Sometimes directly from the sprue plate to the pot. Sometimes I let up to a half dozen sprues accumulate and then put them back in the pot. I dump my boolits from the mould onto a towel in a 9x13 cake pan. I don't want the sprues accumulating too much because I want the boolits to drop on the towel to minimize any damage to the boolit while it is relatively soft. Hitting a sprue isn't as good as the towel so I've got to get the sprues out of the way. I also don't use a thermometer. Maybe I'm just lucky as I don't get really large boolit weight variations. I set the pot (old 20# Lyman) thermostat high and leave it there. The moulds get preheated on the edge of the pot while the whole shebang melts. When the lead is very "liquid" I flux and skim and then begin casting. When the pot is about 1/3 empty I add ingots and repeat the process if I need more boolits. Usually I'm tired of casting at that point and shut the heatvoff. I always start with a full pot. The last string of 35-200's I cast and weighed were nominally 207 with a high of 208.5 and a low of 204.7. That session was ~200 boolits. One of the reasons the weight variations are so small is I examine the boolits as I cast and cull ruthlessly. ANY flaw, no matter how small goes back in the pot. The bases are examined when I open the mould. If they aren't completely filled out with sharp edges they go in the reject pile and go back in the pot with the sprues. Inclusions, slightly rounded lube grooves, slightly different color of the nose, etc all go back in the pot. Demand perfect boolits, find a casting routine that fits your personality and your moulds, and have at it. Have fun and enjoy the hobby. BTW I've only been at this for 40+ years so don't get discouraged easily. Demand perfect boolits and adjust your routine until you get them. You'll find your rejects will go way down as you gain experience and perfect YOUR routine. FWIW Pilgrim

[chadschroeder]

just a little update! I purchased some 20-1 alloy because the directions in the lee mold said 95% to 5%. Remember its the 125g FN. I am still consistently casting 128g-130g bullets now. So i got the 5g variance taken care of. I purchased the Lyman Thermometer and i am casting around 700 deg. Just for giggles, i heated up my mold so it started casting frosted bullets so i know, or have a better idea how hot is too hot. But even those where 130g. I am thinking maybe its just the mold. Now the Lyman casting book says 10-1 alloy but thats not 95%-5% like the directions say, right? Also i can't even find 10-1 mix.