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Moulded bullets came out undersized
Hi all.

Well my tale goes like this.  A fellow shooter has been teaching me the art of casting our own balls & bullets.  He's been casting for many years so I was happy when he told me he would show me the ropes .

Anyway, to add to our choice of cast bullets I ordered the Lee prescision .54 REAL mould.  I left the mould with him when I went out to pick up some lead from the local scrap metal merchant. I got a nice bag of roofing lead off cuts that had just been bought in by a roofer.

So I return to the casting shed ( his old garage ) and he has made himself a couple 100 whilst I was away, this all but emptied his helming pot.  We then fed in my lead and he continued to mould around 300 for me. 

Now we went to the range this afternoon to try out the new REAL bullets, he has a .54 Thompson Center Arms Renegage and I have the .54 TCA Hawken.  My first 3 shots took out the 10 at 35yds, now his first 3 shots missed the target completely,  he says the bullets just drop down into the barrel where are mine need to be hammered in with a bullet starter.

I tried one if his bullets in my gun and yes it dropped straight in, and my bullet in his gun needed hammering in.

Now the only difference I can see between the bullets he has and mine , is a different lead was used.

Looking at the actual bullets, mine are nice a crisp with sharp edges , where as his are obviously slightly smaller and the edges are more rounded and not as crisp/sharp looking.

Is the issue with his lead ? Or could something else be causing his shrinkage ?


Assuming all the bullets came from the same mould fillout can be improved by adding tin, increasing the alloy temperature and increasing the mould temperature.

If this was new mould then it will take time to break in if you haven't pre prepared it by putting it through at least three heating and cooling cycles. Also sooting the cavity or using mould release will degrade fill out, the only thing that should be put in the cavities is alloy, if the bullets won't drop then there is a mechanical issue that needs solving, very common with the poor quality Lee moulds.
A clear example of your friend either not having heated the mould sufficiently or of having the lead at too low a temperature.   The mould AND the sprue cutter must be heated prior to casting.  And the interior should definitely be smoked with a lighter or candle prior to casting.   Read the instructions provided with the mould.    I have at least a half dozen Lee moulds of all bullet shapes.   Along with custom and RCBS moulds.   I have had no problems with Lee and have cast probably thousands of bullets and balls.    Pre-heating the mould and sprue plate, lead at the right temperature (experience) and a good smoked mould will produce fine bullets.
Thanks for all the advice guys.

It would seem , that the REALs he cast in the morning are all undersized , whereas the ones he cast a little later on are absolutely fine. I'm in agreement (now ), that the issue is more down to the heat of the mould.  When he cast my REALs he had already cast at least 100, then left the mould on top of the pot , while he waited for me to arrive. ( about half hour later ). So "now" it seems obvious that the mould was a lot hotter when mine were cast.

My next journey will be down to the lube I use on these REALs , that will come in another topic , coming real soon ?
If your friend cast 200 whilst you were away, I do not think it is heat that made the difference.
I am quite sure his was a different alloy. It is well known that differing alloys can be used to create larger or smaller (to some degree!) projectiles from the same mould.
Yours was near pure lead. Try taking one of his unused bullets and one of yours;
Place them nose- to- -nose in a vice and tighten it up. See if both deform equally, but it is my bet that your bullet deforms first, being purer (softer )

All the best from a frozen and snowy Western Canada.
1) different barrels different dimensions (maybe) there is no such thing as an industry standard.
2) lead alloys shrink more than pure lead but pure lead is a "bst'ard" to get it to get it to fill out the mould properly and requires dangerously high temperatures.
3) with REAL bullets sometimes a wrap /patch of handkerchief thickness cotton improves accuracy /seal although on paper it should not be necessary theoretically.
Vince, I can only think you are not preheating your mould and sprue if you need 'dangerously high  temperatures' whatever they may be.     Preheating in vital.   As is the smoking.   The mould should be sufficiently hot that the first bullet cast  will be perfect.  And don't forget the sprue cutter.  That must be preheated as well or it will cool the lead as it goes through and the lead will not form a sharp edge on the base of the bullet.   I use a blowlamp, being carefully to use a low flame and to heat the mould and sprue cutter evenly to ensure no warping.   And yes, pure lead will cast perfectly.   And I cast everything from .600 Snider down to .300 Rook and balls of all sizes, all of pure lead.

Industry standard?   Wider variations are possible between different repro brands.  Originals from state armouries will have been built to the same tolerances with go, no-go gauges.  Those tolerances in the 19th Century may be greater than with today's precision equipment but were still surprisingly small.  Of course originals may have suffered wear to the bore over their long life, dependant on the level of use and maintenance.   Breech loaders also had to contend with corrosive primers.

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