Need some ideas

[kbstenberg]

I need some help! Recently i have got 3 GB molds the 503, Noe 429215, Noe .311041. My problem all the molds drop bullets smaller then what the design calls for. All the people i have talked to that have gotten the same molds do not have the same problem. And with all 3 molds doing the same. My conclusion is that something in my casting process is causing the problem.
My alloy is 50ww/50pure for pistol bullets strait WW for the rifle. I don't have a tester to calculate BHN.
I do not have a thermometer yet. All I can go by is the setting on my Lee pot about 8
I warm up the molds on a hotplate. Finish warming in the lead melt. Cast as quick as i can till bullets frost. Then slowdown.
I wanted to try to find some answers here before i start to Lapp any molds.
Kevin

[BABore]

Start by cleaning the mold well with brake cleaner and soft tooth brush or similar. Don't care if you already have, do it again, even twice. As you don't have a thermometer you can kind of go by how long it take parafin to ignite in your pot. If it lights up in a couple seconds, it's likely in the 725 F+ range. That's close enough. Put a thermometer on your to buy list soon.

You should probably check with NOE before taking this next piece of advise. Up to you though. I dip the corner of my blocks and sprue plate into the melt for 15 to 30 seconds, then wipe the lead off and begin casting. On the first pour it may take the sprue 15-20 seconds to solidify. Pace your casting until it take the sprue 3-4 seconds to solidify and change from shiny to dull. That is about where you want to be. I maintain this condition with a small high speed fan and casting rate.

You didn't mention your pouring method, ladle or BP pot. Alloy flow rate is extremely important. Filling the cavity fast help tremendously. The bigger the boolit, the more flow you want. Alloy doesn't make any difference to me, nor does the amount of tin. I have no real pouring difficulties with even pure lead. I use it on occasion, but don't use it to fix mold, temperature, or pouring problems.

If you have the ability, post some picture of your small boolits and tell us how you pour them. Sometimes just a touch of smoke on the cavities will help an aluminum mold. A clean aluminum mold will cast well without smoke if you have it hot enough. Please don't confuse a hotter pot temperature with hotter mold temp. As long as the mold is hot enough, you can run your pot temp quite low.

[BruceB]

Kevin;

If all three moulds are "casting undersize", and NO ONE ELSE is reporting problems, then statistically I suspect you just might have a measuring problem, not a mould problem.

Try measuring a few commercial jacketed bullets with whatever device you're using, and see what transpires there.

Just a suggestion, sir, but you're surely not selected by fate or whatever to be the ONLY caster to receive multiple undersize moulds, especially from NOE....are you?

Good luck.

[outdoorfan]

I dip the corner of my blocks and sprue plate into the melt for 15 to 30 seconds, then wipe the lead off and begin casting. On the first pour it may take the sprue 15-20 seconds to solidify. Pace your casting until it take the sprue 3-4 seconds to solidify and change from shiny to dull. That is about where you want to be. I maintain this condition with a small high speed fan and casting rate.



I pretty much do the same thing, but I usually have to leave the mold in the melt a little longer to get it up to temperature. I don't have a thermometer, and I haven't felt a great need for one. If the mold is too cold, I get wrinkles and bad fill-out. If it's really hot, the boolits will be frosty but remain the proper diameter. If it's really really really hot (like when I tried Bruce B's two-pour method for soft noses, which involoves leaving the mold in the melt to remelt the alloys) then the boolits came out .002-003 undersize.

Checking your calipers against a known bullet diameter, like was mentioned, would be a good idea. You didn't mention how undersize they are.

[largom]

Kevin, I use a Lee 20# pot and I have 2 thermometers. The setting on my Lee pot for 725 Deg. is 5. I suspect your alloy is too hot. Follow the advice BaBore gave and while others do not use a thermometer I would be lost without mine.

Larry

[Echo]

I had a similar problem and improved the situation by using a harder alloy. Initially I was using WW+2%Sn. When I went to 50/50 WW/Lino, I gained half a thou.

[Blammer]

I'd go with the above, get a j-word and measure it and see what is says. Maybe your measuring tool is off.

may even want to set your tool to zero, give that a try too.

and yea, BABore's suggestions are also very good and spot on.