Would like some feedback about first casting experience

[horseman308]

I just finished my first batch of cast bullets, and I'd love some thoughts on what I could do to improve. I'm loading for a Pedersoli Sharps in .45/70. The alloy I mixed was 20/1 lead to lead-free solder (95/5 tin and antimony) - I basically mixed 20lb of scuba weights and roofing flashing with 1 lb of the solder in 5 lbs increments. I used a Lyman Big Dipper casting furnace with the 10 pound pot.

The mold is a Lee 459-500-3R. I know it's probably not ideal but I picked it up a year ago when I had an Amazon gift card. I figure I can at least try it out before moving up to a Lyman Postell or something. I kept the alloy temp about 675 to 700 degrees.

Such much for background. I cast about 100 bullets that were good enough to keep and probably did another 100 or so that were rejects while I tried to get the hang of the technique and find a temp that wouldn't leave wrinkles.

Here's my biggest question: 2/3 of the bullets dropped st an average of 475gn, another almost 1/3 were about 478 average, and a small handful were over 480gn. I sorted them by 3-grain spreads. One single bullet came put at 500gn, and the next heaviest were 5 bullets that were 484 to 486.

Most of the bullets dropped frosty, rather than shiny, no matter the temp, but I don't know how much that affects things. I did degrease and smoke the mold prior to use.

So, why might i have light bullets, and what should I do different next time if these don't shoot well?

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[Yodogsandman]

Mostly, your large weight variance will go away after more practice. Sounds like you did great for a first session! Photos help, let's see them!

[mehavey]

1. Frosty bullets will have no effect
2. +/- 2gr in a 500gr bullet will have virtually no effect either.

Press on .... :happy dance:

[milkman]

As mold temperatures fluctuate, the mold will expand and contract, which means the cavity will also expand and contract. boolit diameters will then vary and weight will vary with diameter. The large diameters ( heavy ) usually shoot best.
Sounds like you did fine for a first attempt, just re-melt anything that doesn't look good and try it again. The frosted ones are caused by high temperature. If the mold is a 2 cavity, try giving it a 15 - 30 sec. rest between casts after it gets hot enough to frost. You want the sprue to harden about a slow 3 to 5 count after pouring.
I use that same bullet in my 45/70 and find it to be very accurate.

[Grmps]

horseman308 Welcome to the addiction

1% bullet weight difference will have little to no effect on accuracy. .475-.460 are really close to the 1%
You learn to fill the cavities the same way (watch the lead flow going in)
watch the alloy and mold temp, check shinny boolits, frosting and a divit taken out by the sprue hole
Make sure you have a firm (not hulk like) grip on the handles so the cavities are closed the same every time.

the google custom search box (top right of the forum) is your best friend
and LASC has a lot of good reading/information


The only way you can really tell 100% is to test the different weights with the same power load on targets with the same gun.

[brewer12345]

You did fine. I would invest ten bucks in a hotplate before you do your next cast and use it to preheat the mold. That should help a lot with the wrinkled and frosted stuff. Anything within a 5 grain spread on a slug that big I would not worry about. I cast a lot of 38 boolits and typically get most of them to be +/- 1.X% of the average weight of the lot. Makes no real difference to me. Maybe if I take up benchrest shooting I will care.

The nice thing about casting is that you can just recycle your rejects.

[kens]

I am not as 'expert' a caster as some on this forum, but I will take at stab at it.
your described alloy appears ok as described for something like 45-70. 45-70 doesnt require a high tech alloy. we're not talking high velocity here.

you got a Lee mold, Lee mold mold by itself is OK, some folks don't like Lee, but it is ok, it is do-able.

you say the bullets are frosty. My experience is that antimony in ANY amount results in frosty look. this doesn't harm anything, it only tells me there is some amount of antimony present in the alloy.

when casting of pure soft lead, and you got frosting, then you are too hot. IF there is ANY amount of antimony in there, then all bets are off on the frosting.

If you got light bullets, I suggest look at wrinkles, and soft edges. A good bullet should come out with crisp sharp edges at groove bands and bullet base and sprue cut-off.

If your edges are soft (rounded) you are too cold, oily, or any other all-bets-off abnormality.

Did you pre-heat your mold at the start? if you did NOT pre-heat then it might take you 100 bullets to get up to a stable temp of alloy & mold.

If you are a new caster, it may take you 500 bullets to get into a stable rhythm of casting, temp, sprue cutting, and closing mold.

If you are using aluminum mold (Lee) and IF you are casting hot, the bullet can grow in diameter an weight.

Some days I cannot get a good bullet to drop out of a mold, and just turn off all the heat and put it all away. try again another day.

Some days I cast hundreds upon hundreds with nary a cull in the batch.

If you throw a few bullets particular heavy, the mold was not likely fully closed.

If you are a new caster, and your majority of bullets are light, are all your bands and bullet base full and sharp??

[35 shooter]

Sounds like you did great for your first! I would echo pre heating your mold on a hot plate before casting so you cast good boolits right off the bat, or within 5 to ten pours.

Pour a generous sprue and as has been previously suggested, i like to see the sprue harden at a count of two to 5 seconds. Any more than that, the mold or the melt is probably getting too hot.

As has been said, frost doesn't hurt a thing. If the sprue is taking too long to harden(you'll see it change color as it cools), you can touch the bottom of the mold to a wet towel for a second or two, or as has been suggested, let the mold cool a bit before pouring again.

You'll get better and better at consistency the more you cast. I would echo the importance of a consistent "grip" pressure on the mold handles also.
The as cast dia. and consistent weight of the boolits will get better and better as you go with practice.
As you read more and cast more, you'll began to catch on to all sorts of little things your doing OR not doing lol.

Again, without seeing pics lol, it sounds like you did very well indeed for your first time.....load up the ones that filled out and have a good time!!!

[Bent Ramrod]

I found that for tightening up the weight variation in big boolits, a lead thermometer is a big help. For me, a reading in the 725-750 degree range seems to give the smallest spread, and the fewest light ones.

A good, consistent grip on the handles and constant checking for tight closure (no lead particles or smears between or atop blocks; pins seated fully; sprue plate properly tight) reduces the incidence of extra-heavy ones.

I use a RCBS ladle for anything at or over .38 caliber rifle sizes, and hold the ladle on the sprue plate for a count of 8, then leave a reasonable puddle to handle the dimple that forms in the middle as it solidifies. For match use, I weigh each boolit and segregate them by the nearest grain weight. Aluminum blocks seem to give a wider weight variation than iron or brass, probably because they heat and cool so quickly. A steady casting rhythm helps with this.

[Smoke4320]

For a first time caster I would say you did well . 2% variation in a 500 grain bullet is just fine ..
as said above a hot plate to preheat or keep hot and a thermometer in the pot will help greatly cut down the variances
Watch for wrinkles and poor fill out on the driving bands

Pics or it didn't happen :) :)

[horseman308]

Thanks for all the feedback. I made sure to heat the mold by resting it above the furnace for several minutes, and that helped after several pours. I do use a thermometer and indeed found that about 700 to 725 degrees worked well for better consistency. I made sure not to keep anything with rounded bases or edges.

I did find last night that I had some lead splatter on the inside mating surfaces of the mold, and thus it doesn't close fully. I'm sure that has an effect on the weight variation, but I found that my bullets are nearly all out of round by about .003", so I'll have to melt them down and start over.

I tried to reheat the mold but that didn't do anything to remove the splatter. I don't want to mess this up already, so how would y'all suggest I clean up the mating surfaces?

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[mehavey]

Get a:

- 3/8" flat-brass strip at any hobby store to scrape off the gross splatter
- Brass/bronze toothbrush (any hardware store) and go gently at any remaining

[lightman]

Sounds like a successful first attempt at casting! A hot plate will help get your mold up to casting temperature without so many rejects. A cheap one from Walmart is $12. Having used the mold already will help too, as some molds need a few heat cycles to get broken in. Your weight variation is not bad and will improve as you develop a rhythm and learn more about controlling temperature. All in all, you're off to a good start.

[Wayne Smith]

Lead splatter - you probably have a bamboo skewer in your kitchen drawer - grab one and use both ends. Heat the mold and wipe it with a piece of burlap - will do the same thing.

You didn't specify a two cavity or six cavity mold - if six be careful not to grip the sprue plate handle as you pour - this opens the mold slightly and allows the splatter and the oversize/oval boolits.

I echo the hotplate - if a coil plate get an old 10" circular saw blade to put on it and use it to pre-heat your mold. It does make a world of difference.

You have done the most important part - melted and poured lead. Now it's gathering experience and developing specific questions to ask us.

[horseman308]

I've had a few free minutes this morning and was able to get the mold cleaned up. I cast a few dozen. While the out-of-roundness improved, it didn't go away.

I got down to about .0015" out (.4585 one way and .4600 the other measured with digital calipers, turning the base 1/4 turn at a time) on average across about 12 sample bullets. Some were nearly perfect round but most were about .0015" to .002" out. Also, no matter how clean I got the faces and pins of the mold, no matter how hot, there was still a visible gap at the nose. It got much smaller as the mold heated of course, but never fully closed. Obviously this is not preferable.

However, is there an "acceptable" range for out of round bullets? I wasn't sure if the obduratuon when firing would make a certain amount of variance immaterial, since - in theory - the bullet would then completely fill the bore and become fully round (except the nose of course, which would be a problem, no?). Hope that makes sense....

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[Wayne Smith]

Your barrel is the ultimate sizer. As long as the boolit chambers it will be sized down to the barrel size. We want a little of this but want to minimize it - depending on the relative sizes of the barrel and the chamber.

[wv109323]

Unless you a serious top competitor, I think you will find your bullets acceptable. Pick 10 of the worst and try them.
I shoot bullseye pistol. I cast a bunch of bullets. I picked the obvious rejects out. The unfilled cavities,the wrinkled bullets but not a real close inspection. I then picked 10 of the worst boolits I could find. These would normally be rejected on a second inspection.
I loaded those bullets and ransom rested them. The group was 3 X 1 3/4 inches at 50 yards. I then ransom rested 10 commercial cast boolits. That group was 1 3/4 x 3 inches. One group showed vertical displacement and the other horizontal stringing but the same size CTC.

[robg]

Big boolits need to be cast at a high temp for some reason to get consistent weight 2% variation is no big deal should shoot fine as long as the bases are good.

[KCSO]

For 45-70 accuracy loads I use an Ideal dipper scoped full each pour through the pot. I hold it to the mould for a long three count and then slobber a little extra across the sprue plate and watch as it sucks in. My lead id mixed in 50 pound batches from pure lead and tin. I size in a Lyman sizer luber with bear oil and bees wax and size to 2 thou over bore diameter. I weigh each bullet for match shooting and divide them into 1 grain lots.

This is a long way from where I started casting over a wood stove with an old surplus mould and lubing with tallow rubbed into the grooves and seated over a case full of Dupont black in 1890 Frankfort cases. They shot fine in my trapdoor and I sure had fun with them.