Lyman #452-651 325GC

[warboar_21]

Just received this mold from Midway yesterday and tried casting this morning. Using COWW with silver solder added from a Lee 10# bottom pour pot I could get no better than .451 on average and only a couple that were near .452". I tried adding more solder to the mix and tried increasing the temp to the point where the bullets were dropping frosty. Results were still the same.

I switched over to the Lee 450gr 45-70 and it to was dropping undersized. So I switched over to a mold that I have had for awhile that I know that drops properly sized bullets and the bullets dropped perfectly what they have dropped forever.

I have never had a Lyman mold that has dropped under advertised diameter. Lee on the other hand is almost expected to drop a bit small.

Am I doing something wrong? Is there something I can do to get the mold to drop as advertised diameter bullets?

Thanks in advance

[runfiverun]

try pressure pouring some.


then get out the lapping compound...

[Baron von Trollwhack]

I have a 452651 Lyman from approximately 6 years ago. With Lyman #2 type alloy it is throwing just a very little over .452 and is nicely round. I enlarged the sprue hole diameters about 10-15 % and recut the sprue plate bevels and then lapped the underside of the sprue plate with sandpaper on my drill press table to get a good sharp cut. The mould works very well now.

I have long considered that many of Lyman's mould designs need a slightley larger sprue hole to get any sort of improved pouring technique to cast to nominal dimensions or get a uniform fill. I have never seen this mod discussed here. Sprue plates are cheap it you don't get it right.

BvT

[John Allen]

I have a 452651 Lyman from approximately 6 years ago. With Lyman #2 type alloy it is throwing just a very little over .452 and is nicely round. I enlarged the sprue hole diameters about 10-15 % and recut the sprue plate bevels and then lapped the underside of the sprue plate with sandpaper on my drill press table to get a good sharp cut. The mould works very well now.



I have long considered that many of Lyman's mould designs need a slightley larger sprue hole to get any sort of improved pouring technique to cast to nominal dimensions or get a uniform fill. I have never seen this mod discussed here. Sprue plates are cheap it you don't get it right.

BvT


Hey Baron, when you enlarge the sprue plate hole are you just ding it with a drill bit and then clean up the sharp edge or is there another technique? I think this is the problem I am having with my heavy 452 mold.

[warboar_21]

Pressure pouring?

not sure how to do that.

I just tried drilling the sprue hole larger to see if that will help.
have to try again in the AM.
thanks again for the help.



try pressure pouring some.


then get out the lapping compound...

[warboar_21]

Well I was able to pour a little lead through the mold. Looks like they filled out somewhat better but still just barely makes .452". So I guess my next move is to try lapping to get slightly larger.