.45-70 Casting Blues

[Tennessee_Ted]

I'm not exactly what you would call a veteran bullet caster, and I just tried my hand at casting some 405 grain bullets for my .45-70 with a Lee 10lb bottom-pour pot. I've previously cast several hundred pistol bullets with this set-up, but the .45-70 bullets are giving me some serious problems.

The bullets aren't filling out, and it looks like they're composed of layers. I've got the melt as hot as the Lee pot will get it, but no matter how many bullets I cast or how hot I get the moulds, I keep getting the same result. I would assume this is due to the air in the large bullet cavities cooling the melt too fast as it fills up. Any other suggestions as to why this might be would be greatly appreciated, however.

Assuming that is the problem, though, is there a way to make this work with the bottom pour? If not, would ladle casting be advisable, and if so, would a hot plate be a sufficient heat source?

Thanks,
Ted

 

[Lee S. Forsberg]

The molds have been cleaned, no oil in them? I have the same problem when I start to cast and dosn't go away till the mold gets to the right temp. Using a Lee mold shouldn't take that long, with Iron or Brass takes a little longer. Pre heat the mold by setting on top of the pot as it warms up.

 

[tightgroup tiger]

If you are holding your mold up tight against the pour nipple the mold could be getting air locked before it fills.

I hold my mold about an 1/8"below the nipple to let the air out as the lead goes in.

If the pour hole is partial blocked and you aren't getting a full stream it may be taking to long to fill the mold. I've had that problem also.

Short of that, like Lee said, it sounds like the mold is cold. I cast at about 650 deg and preheat my mold for about 1/2 an hour over the pot before starting.

You didn't say what kind of mold your using and what it's made out of.

A cold sprue cutter causes me more trouble than the mold. I put a lot of extra lead on the sprue cutter at the start of a session to help heat it up. Again, try holding about an eighth inch below the pour hole.

Just some suggestions.

 

[rcmodel]

+1

1. Smoke your Lee mold with a flame from a match as in the owners manual.

2. Hold the mold a little below the pot spout to allow air to escape.

3. Immerse one corner of the mold in the lead pot until lead no longer sticks to it to insure proper mold temp.

rc

 

[KansasSasquatch]

And maybe to add to what's already been stated/asked but have you adjusted the flow of the bottom pour yet? I have a Lee 20lb bottom pour and I know it's adjustable. I'm sure the 10lb probably is too. When I first started casting, not long ago, I found that the faster I allowed the valve to pour the better (without excessive dripping, appears 99% of Lee bottom pour pot drip a little). When I had it set to flow slowly I'd get bullets like you describe. Mould and lead temp are just as important though.

 

[NuJudge]

Add a little Tin

A couple percent Tin does several good things, all at the same time: it dramatically lowers the freezing temperature, as well as allowing the liquid to fill in where the Lead has shrunken on freezing. The handiest source is Lead free solder.

 

[RugerBob]

I was thinking oil in mold. I hold mine an 1/4" under and tilted to let air out. I use the single cavity 405 hollow base Lee mold.

 

[jmorris]

I have a 500 grain mold that I also have to tilt and have the sprue cutter very hot, to get good results.

 

[loose noose]

What RC said, he usually knows of what he speaks, after my molds sit for a long time I will usually use an old farmer match to smoke 'em, then heat 'em up before even thinking about starting.

 

[MEHavey]

1. Get a thermometer if you don't have one. Some cast hotter, but a steady 700 degr will give you perfect bullets -- be it pure lead, wheel weights, 1:30 or true Lyman #2

2. Get the mould up to temp first. RC suggested corner dip in the lead pot as one method, I began pre-heating my moulds underneath a small/cheap (WalMart/Target) pot on top of a hotplate a couple of years ago (preheat while the lead heats). It's been night & day.

3. Get a standard RCBS or Lyman lead dipper out of Midway and use that instead of bottom pour. A full dipper in contact with the sprue hole for a two/three-count will fill out the mould.

4. Allow at least 15-20 seconds cooling time before opening the mould. Heavy bullets take a while to solidify completely. The sprue should be hard to cut, but still do-able using the palm of your gloved hand. Adjust according to what you see (feel) happening

The big/heavy 45s are a graduation test in cast bullets.
Once having mastered their technique, everything will be child's play in hindsight

 

[dagger dog]

I kind of watch the funnel on the top of the sprue plate and let the melt hit the funnel
and swirl it into the mold, if you try to hold the spout right on the sprue plate the air can't get out of the mold fast enough and it cools the melt.

Another thing is over lubing the sprue plate screw, the excess will run into the mold without you noticing and it will cause problems.

Over smoking the cavities or using anything other than a match will leave to much soot of the wrong kind and cause wrinkles.

Crank up the heat until you get fill out, they will frost up but then start to reduce the temp until the frosting goes away.

Over heating the mold can cause problems too, use a wet towel to touch the mold on if you think it's getting too hot. Try to keep a steady rhythm it helps on keeping the mold the correct temp.

 

[jmorris]

Over smoking the cavities or using anything other than a match will leave to much soot of the wrong kind and cause wrinkles.

All I ever use is smoke from an acetylene torch. Works like a charm.

 

[tightgroup tiger]

Over smoking the cavities or using anything other than a match will leave to much soot of the wrong kind and cause wrinkles.

I agree, I gave up smoking my aluminum molds completely. I've just never had to do it. When your mold is the right temp and you are cracking the center bolt "before you open the mold" the impact will usually knock them loose. You open it and let the air hit them, then try to knock them loose, they are going to stick.

I've noticed with my Lee molds that when they are just warming up they will release really well and make wrinkled bullets, then as they get hotter they stick, then they get a little hotter they make good bullets and and release well, then they get hotter they frost the bullets.

You really need to have a thermometer to know when your lead is the right temp.

The mold, you have to learn where it likes the temp the best to work the best it can.

Kind of like handloading for a rifle, you have to find the sweat spot.

I just finished casting 4k of bullets and it was a lot of fun for me.

 

[flashhole]

An easy way to heat the mold is to keep the first few bullets in the mold longer. I like the tin suggestion too. If you are having problems with the lead flowing adding some tin is the answer.

 

[dbmjr1]

A suggestion regarding tin.

Go to garage sales. Pewter trinkets are almost pure tin.

The Statue of Liberty has alloyed many a pound of lead for me.

Pewter plates, mugs, etc are all fair game.

 

[flashhole]

Too bad they don't have a like button because that is a good tip for sourcing tin.

 

[grubbylabs]

What every one else has said, get the mold a little hotter, run the mold hot and the melt cool, and you will have good bullets.

Adjust the flow on the pot so it flows into the mold quickly but not so quickly that it creates a mess, and experiment with the mold and melt till you have the melt hot enough to keep the mold up to temp but not so hot you mess up your alloy. There are quite a few threads on this subject at the castboolits forum.

I used to just use the pot and melt to get my molds up to temp, but I found a hot plate to be much cleaner and quicker.