Weighed some of my bottom poured today - curious about ladle results

[Mike W1]

Not that I really plan to switch to a ladle but I wonder how much more consistency one might expect from that method. I'm pretty sure these bullets will perform better than I can shoot. They're part of about roughly 400 I cast in that little session.

Weighed 81 by random pick
AVG 224.04
Hi 224.9 (+ 0.9 variation)
Lo 223.0 (- 1.04 variation)

223.0 2
.1 1
.4 5
.5 2
.6 7
.7 1
.8 6
.9 6
224.0 5
.1 12
.2 11
.3 7
.4 2
.5 4
.6 7
.7 1
.8 1
.9 1

Had a few wrinkled ones which I can
generally predict by not hitting the center
of the sprue hole when pouring. None of them
exceeded the AVG by more than ± .5 grs.
Could have kept them!

[Hannibal]

There is a thread in this very forum titled 'Consistency Applied' that you might find interesting. Lots of good info.

[41mag]

You did real well.

What I found out when I was getting rolling was that the alloy and mold temp play about evenly in keeping things on a close tack. If your alloy temp sways from say 680 up to around 750 back and forth your bullets will have a bigger spread. Same with the mold, when your first starting a session and have a cool mold your bullets will weigh more than after you get up to frosty territory.

Here are a couple of decent post to read through if you feel up to it,

Boolit weight variation (http://castboolits.gunloads.com/showthread.php?161636-Boolit-weight-variation&p=1805114&highlight=#post1805114)

Analysis of cast boolit weight variences (http://castboolits.gunloads.com/showthread.php?120938-Analysis-of-cast-boolit-weight-variences)


We weighed up plenty in that last one.

[Mike W1]

Interesting reading above. Years back I inherited quite a lot of rejected cast bullets made out of linotype from some old boy that was evidently quite a bench rester. The rifle must have weighed 20 lbs. At that point I'd never cast a bullet that looked as good as his rejects! Anyway I learned a thing or two recasting those rejects with his moulds. Wish I'd saved those results but decided I could cast good bullets with the perfect casting alloy anyhow. Gave up the rifle casting long ago though.

Just feed my 45's and a 9mm now and brew my stock of telephone sheath and sleeves to suit. Will never be without PID's again but still believe with bottom pouring the important things are a steady flow and centering the sprue hole. Obviously one needs an adequate sprue but personally I find that to be much smaller than most advise as long as I adhere to those two rules of thumb above.

[MBTcustom]

What alloy were you using at what temperature?

[Mike W1]

What alloy were you using at what temperature?

My mix below. 715° PID controlled.

2 lbs Tin
10 lbs SuperHard
141.4 lbs ingots
(ingots are telephone sheath lead that
run around 9-11 BHN and obviously
have Sb in them but who knows
how much)

[MBTcustom]

Typo see post #20
A pretty close estimate of your alloy there is 2.5% tin, and 2% antimony. It should cast very well.
(BTW, the mold wants to cast 224.1 and that's the target weight you are shooting for with that alloy).
Typo see post #20
I plotted out your bell curve, and at first blush, I would say you might try bumping your temperature up 15 degrees or so, but it really looks like mold temperature needs to be controlled better (which is very hard to do with those little 22s).
You have to be Johnny on the spot, and use a hot plate to get you up to temperature. Once there, try to pour a large puddle on top of the mold as close to the same size as possible and as large as you can get without it running off the side of the mold. As soon as the surface tension breaks and your puddle runs off the mold, you lose all the heat it was carrying along with the alloy.

When you prep your mold with the hotplate (I highly recommend NOEs mold thermometer to make sure you are up to operating temperature) the trick is to figure out the most consistent pour timing, and never miss it. If you ever hesitate more than a few seconds, return it to the hotplate and go wash your hands and sip some coffee or something.

Change one thing at a time, and check your progress with the bell curves. You may be surprised how tight you can cast those little pills!
With that alloy, I would be looking for 95% of them to drop +-.2 grains, perfectly filled out, no wrinkles, and +-.0001 with a micrometer.

[Mike W1]

Took a peek at that NOE thermometer but that picture didn't really help my imagination that much. I'm assuming they're using somehttp://noebulletmolds.com/NV/images/NOETEMP004.jpgsort of drilled/tapped TC to do the trick. Can't say that object resembles a Lyman DC too much though. Might be interesting to fool with one if I knew a bit more about how to adapt my moulds. TC's are only reasonably accurate and my VOM has the temperature capability. Don't happen to know if Auber's has an appropriate probe do you?

[MBTcustom]

Actually, my PID from Auber came with a stubby little TC that could be screwed directly into the mold. I was kicking around the idea of using it, and building a PID that would monitor mold temperature of the mold by using it on the hot plate.
Since the mold would be at operating temp as it was being used, the hot plate would be ready to recieve the mold at any time. It would already be compensating for the cooled mold, if you fell off the wagon while casting, so recovery time would certainly be shortened I'm thinking.

[Garyshome]

Not sure but the weight behind the bottom pour should be more then with the ladle. Also has more velocity. Boy this is sure a strange subject to be talking about, i wonder how many people ever would think about anything like this?


Good PR work is under rated and over looked.
I just trained my wife right. She thinks it is SUPPOSED to look like that!

[Mike W1]

I've been hesitant about drilling a mould. Awhile back I JBWelded a tapped piece of aluminum to a mould and used a threaded TC to cast some bullets. That was supposed to stand temperatures of 550°. Nice idea I thought but it didn't hang on long enough to come to any valid conclusions. Possibly I didn't do something quite right. Was surprised to find that the TC cable really wasn't much in the way when casting though. Used one of these probes from Aubers to monitor the temperature on my warming shelf with some success. Think that'd be feasible to mount on a mould?
http://www.auberins.com/images/TC-K6a.jpgTC-K6

[MBTcustom]

That's exactly the one I was talking about, and yes, it would be absolutely feasible. Just drill and tap a hole, and screw it in. The hard part is figuring out how to read it (I'm a mechanical person who is electricity stupid).
Let us know how it works out for you!

[Mike W1]

That's exactly the one I was talking about, and yes, it would be absolutely feasible. Just drill and tap a hole, and screw it in. The hard part is figuring out how to read it (I'm a mechanical person who is electricity stupid).
Let us know how it works out for you!
Well reading it wouldn't be too hard, either a PID unit or a VOM that reads temps and mine does. Long as you're a mechanical person. I don't think I'm capable of tapping the mould. Aluminum is about my limit, not steel or cast whatever these Lyman moulds are. If I were to tap a small piece of steel and have someone wire weld it to the side of the block wouldn't that work just as well?

BTW all a TC really amounts to is 2 dissimilar wires down in that tip. A change in temperature produces a small voltage and that's what is actually measured and converted to a readout in temperature.

[Mike W1]

Finally found my notes from my JBWeld experiment. They weren't in the right folder. Anyhow this is what little I learned till the weld let loose.

12-13-14

Played with mix of 120414 Alloy mixed with sheath/sleeve metal.
Mixed 4 lbs to 10 lbs sleeve/sheath
Cast 3 slugs for testing

Previous tests with the TC hooked to the bottom of the warming shelf
showed it hit a maximum temperature of about 300° F

JB Welded a piece of 1/2" aluminum to side of #452374 mould that was
tapped for a 6M threaded TC. Set PID to 710°

Hooked TC to mould and cast a pot full. Didn't have mould on shelf for the
full heating period for warmup but it was showing around 200°. Then I
ran about 3 cycles and it was hovering around 298-300°. When sprue
started to cut a little too easily it was 310°. Turned on cooling fan and
mould temp stayed around 296-300°.

When pot was getting low set the mould on the warming shelf and let the pot
heat back up adding about 6 ingots. Mould dropped down to 265° while
this was going on and seemed to be staying about there. A couple casts
brought it right back up to temp and then the JB Weld let loose thus
losing my TC hookup to the mould.

[MBTcustom]

I would greatly discourage any attempt to heat any part of that mold hotter than 750 degrees!!!!
Do not weld on your mold. It will damage it, and then, all you can do is hope it damages it in a way that does not effect accuracy or function.

The blocks are made of ultra machinable iron (not steel). It is a simple matter of selecting he correct tap-drill and tap to produce the threads you require. If you have a steady hand, this job can be done with a cordless drill and a tap in a T handle. The tap does not even require oil lubrication as the graphite present in the iron itself acts as a lubricant.

[AggieEE]

MikeW1 if your meter is anything like my Fluke at the shop make sure that the TC you got is a type K. Red and Yellow leads are the correct color code IIRC. There's a long list of different types of TCs and each one has a differnt use. I had a dental furnace in the shop that was driving me crazy because the TC wouldn't calibrate, automatic cal. A call to tech support and the first question she asked was what color was the TC leads were. Put in the right TC and it worked fine. The client didn't tell me that he "help me" some first.

[Mike W1]

I would greatly discourage any attempt to heat any part of that mold hotter than 750 degrees!!!!
Do not weld on your mold. It will damage it, and then, all you can do is hope it damages it in a way that does not effect accuracy or function.

The blocks are made of ultra machinable iron (not steel). It is a simple matter of selecting he correct tap-drill and tap to produce the threads you require. If you have a steady hand, this job can be done with a cordless drill and a tap in a T handle. The tap does not even require oil lubrication as the graphite present in the iron itself acts as a lubricant.

Didn't know but suspected welding was NOT a good idea. Thank you.

[Mike W1]

MikeW1 if your meter is anything like my Fluke at the shop make sure that the TC you got is a type K. Red and Yellow leads are the correct color code IIRC. There's a long list of different types of TCs and each one has a differnt use. I had a dental furnace in the shop that was driving me crazy because the TC wouldn't calibrate, automatic cal. A call to tech support and the first question she asked was what color was the TC leads were. Put in the right TC and it worked fine. The client didn't tell me that he "help me" some first.

My PID's and VOM all used the K type.

[Mike W1]

A pretty close estimate of your alloy there is 2.5% tin, and 2% antimony. It should cast very well.
(BTW, the mold wants to cast 224.1 and that's the target weight you are shooting for with that alloy).
I plotted out your bell curve, and at first blush, I would say you might try bumping your temperature up 15 degrees or so, but it really looks like mold temperature needs to be controlled better (which is very hard to do with those little 22s).
You have to be Johnny on the spot, and use a hot plate to get you up to temperature. Once there, try to pour a large puddle on top of the mold as close to the same size as possible and as large as you can get without it running off the side of the mold. As soon as the surface tension breaks and your puddle runs off the mold, you lose all the heat it was carrying along with the alloy.

When you prep your mold with the hotplate (I highly recommend NOEs mold thermometer to make sure you are up to operating temperature) the trick is to figure out the most consistent pour timing, and never miss it. If you ever hesitate more than a few seconds, return it to the hotplate and go wash your hands and sip some coffee or something.

Change one thing at a time, and check your progress with the bell curves. You may be surprised how tight you can cast those little pills!
With that alloy, I would be looking for 95% of them to drop +-.2 grains, perfectly filled out, no wrinkles, and +-.0001 with a micrometer.

Had some time to waste today so am wondering how you came up with 2.5% Sn and 2% Sb? I of course don't know for sure how much Sb is in those cable sheath ingots but they run 9 - 11 BHN so there's obviously some Sb in there. Played around with some calculators that I've found online and came up with an arbitrary figure of 1.75% Sb in there to get a BHN of 10 when added to lead. I've a little calculator written in Basic that gets me a 15.1 BHN with those weights inputted. 1.2% Sn and 5.2% Sb. And bullets cast from that alloy measure about 15 BHN. So they must be at least ballpark figures. No way there's 2.5% Sn in there for sure.

Anyhow these are the calculators I've found online so far. Any I've missed that you know of?

Alloy05.xls
Cast Bullet Alloy Mix -v1.2.xls
Lead Alloy Calculators 070612.xls

[MBTcustom]

My mistake! When I was taking a stab at your cable sheathing alloy, I was using a calculator that had the tin in the position that I am used to antimony being in, so the tin ran high.
I redid the calculation correctly and came up with 95.4% lead, 1.3% tin, and 3.34% antimony.
Sorry about that.
The calculator I use is one I downloaded from castboolits that was posted by bumpo628
http://castboolits.gunloads.com/showthread.php?105952-Lead-alloy-calculators
It has all the pure tin and the Roto superhard alloys. I used the custom alloy section and made your cable sheathing 1.5% antimony which gave it an estimated BHN of 10, which is smack dab in the middle of the hardness range you measured (9-11 BHN).

Other than that egregious typo, I stand behind the rest of what I said. I edited the post above to sight my mistake.