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delt167502
03-24-2010, 08:40 PM
I hope someone can help. I just bought a lee mold(457-340) tried casting today, the boolits look good but there is a variation in the weight of about 10gr. the question is what is normal for a 340gr. boolit . using wwfor casting,I melted them dn.and poured into muffin tins. the material is clean and fluxed. if you can help thanks in advance.

montana_charlie
03-24-2010, 09:32 PM
the boolits look good but there is a variation in the weight of about 10gr.
Do you mean to say that the weights of the bullets you cast varied from each other by 10 grains?

...or...

Are you concerned that your nominal bullet weight turned out to be 10 grains different from the 340 grains you expected them to weigh?

You can only expect a clear answer if your question is clear.

CM

delt167502
03-24-2010, 10:07 PM
I guess i didn't make me self clear . the bullets are varying as much as 10gr.

BrianB
03-24-2010, 10:33 PM
How many cavities does the mold have...just curious.

delt167502
03-24-2010, 10:41 PM
It's a 2 cavity mold ,have seprated the cavities and weighed they both seem to vary.

chuebner
03-24-2010, 10:49 PM
Wow. 10gr. variation seems like a lot. I have the same DC Lee mold and I use an alloy of WW and range scrap. My bullets weigh +or- 1gr. and I like to cast hot, 750-775 which gives nicely filled frosty bullets.

charlie

BrianB
03-24-2010, 10:57 PM
I'll check mine when I get home and see if I have that much variation. I agree, that seems a bit much.

HangFireW8
03-24-2010, 11:25 PM
I hope someone can help. I just bought a lee mold(457-340) tried casting today, the boolits look good but there is a variation in the weight of about 10gr. the question is what is normal for a 340gr. boolit .

I have found a great way to vary the weight of boolits. Nearly fill the cavity in one stream, and then top it off. I'm pretty sure I'm trapping air bubbles into voids near the base of the boolit.

-HF

R.Clem
03-24-2010, 11:45 PM
Similar problem last springs casting session, not using a Lee mould tho.
Left the WW's for pistol and such, went to bullet cores and tin. That problem went away, new problem I am not worried about, 10 grain heavier bullets, but all are within 1-1.5 grains.
I am shooting 550 grain in .45-70 with black powder.

Ray

DLCTEX
03-24-2010, 11:48 PM
If the alloy and mold are hot enough then venting is likely the problem.If the corners are not sharp and well filled, increase the heat to light frosting. If that doesn't fill well, add tin. Bottom pour or ladle? Air gap or pressure pour? Are there wrinkles on the boolits? Tiny voids add up quickly, and new Lee moulds can be trying to get them clean enough to cast well.

fredj338
03-25-2010, 03:42 AM
That is a huge variation. I use the same mold, cast form ww, they vary as little as 1gr. I allow 1.5gr either way from mean weight. I have never had one be more than maybe 4gr off. A 10gr variation may have internal voids or something else going on. Try castin form one cav only & weigh them. You could have one cav slightly off.

243winxb
03-25-2010, 08:30 AM
Mold / Lead temperature

A good indicator of mold/lead temperature is the puddle that forms on top of the mold as it is filled. This puddle should remain liquid for 3 to 5 seconds after the flow of lead is cut off. If the puddle solidifies as you fill the mold, then the lead is probably doing the same thing inside the mold, resulting in a undersized bullet with weight variations.

BrianB
03-25-2010, 03:19 PM
Delt,

I checked mine this morning and I'm getting about 2grs in variation using straight wheel weights. Typically, when I get a variation like that, it is because of mold fill-out. Typically, the band edges will be rounded instead of sharp. I hope you're not like me. Sometimes I'll catch one that is not right when I'm loading after I have inspected them two and three times before...guess I need glasses.

mpmarty
03-25-2010, 05:37 PM
My 45/70 molds are all 350 to 425 grains and cast boolits are weighed and those that vary by more than 1.5 grs are remelted. My remelts run around five percent or less. I've got two LEE Ranch Dog molds and an RCBS 45/405 single cavity. I cast at 725 to 750 degrees F. measured by a thermometer.

steg
03-26-2010, 05:00 PM
I was having the same problem with that mold, I took 243 winxb's advice and that was the cure................steg

delt167502
04-09-2010, 06:52 PM
I corrected the problem. bought a diffrent mold .a lyman 3457122 hp it casts within 2gr. var. is quite a differance in the molds. I tried about everthing and with close inspection there was still a 8gr. difference. A BIG THANKS DEL