casting problems

Ken Hartlein · Post by **Ken Hartlein** » Wed May 19, 2004 10:28 pm

I use the Lyman 457132 also, your problem is a mystery. I wait until mine is very hot before it makes good bullets. In fact if I get interuped the bullet quality falls off. I heat my melt to 790 degrees, and cut the sprue as soon as it turns color. Is your sprue plate adjusted firm against the mold??

Carl · Post by **Carl** » Wed May 19, 2004 10:29 pm

I use both of those molds too. I cast at 800 degrees with 25/1 alloy. After the puddle freezes I count to 10 and break the plate with my hands wearing mits. I have seen the problem you are having if I do'nt wait long enough.

Carl

Bad Ass Wallace · Post by **Bad Ass Wallace** » Thu May 20, 2004 12:29 am

The effectiveness of your sprue plate can be one of many factors.

A) Is it flat? Sometimes they warp upwards away from the mould and cause this same problem

B) Is it too tight? When the mold is at casting temperature, can the plate be pushed sideways with finger pressure. If too tight it can also warp upwards.

C) Is the sprue hole burred? Very hard to cut cleanly with a blunt edge

D) Are you casting in a high ambient temperature? If it's summer, more time maybe required to let the mold dissapate heat so that it doesn't overhead and keep the mold material at or near liquid state.

Lee Stone · Post by **Lee Stone** » Thu May 20, 2004 11:50 am

smoke eater

Another thing you could try. Paul Jones taught me this. Instead of cutting the sprue with a single push, he advised me to use a small rawhide mallet, such as Tandy sells, and very lightly give the sprue chutter a series of rapid, gentle taps. This results in a series of crescent shaped, very smooth cuts and does not risk tearing the base of the bullet such as you described. It leaves a very smooth and uniform bullet base.

Tasmanian Rebel · Post by **Tasmanian Rebel** » Thu May 20, 2004 12:24 pm

Smoke eater, I, like Carl, get these little tear outs when I cut the sprue too soon. Another reason I have got these in the past is traces of antimony in the alloy. You may want to check your lead and tin sources.

Omaha Poke · Post by **Omaha Poke** » Thu May 20, 2004 1:33 pm

Smoke eater, what Lee said works great. You might also make sure that you have a thick enough sprue poured on top of the plate to allow for alloy draw-down. That is what usually causes the black specks you are talking about. They are actually voids in the base of the bullet caused by not having enough alloy to draw down into the bullet as it cools. Randy

Shiloh Sharpie · Post by **Shiloh Sharpie** » Fri May 28, 2004 6:54 am

If they are both Lymnan, try switching the sprue plates. If the problem follows the plate get it replaced. I have after market sprue plates for my Lymans. Mine were made by Bob Roller who may be retired. But others make them as well. Also, I find that if the alloy is hard, the sprue cuts worse. 1:20 is as hard as I like for good bases. 1:25 is better so long as it shoots accruately in your barrel. If you have antimony in your mix I think your problem could be worse.

powderburner · Post by **powderburner** » Fri May 28, 2004 9:39 am

I have a couple of those moulds as well an if after they get hot and you have a puddle of lead on top , as soon as it solidifies touch it to a damp cloth or sponge for a 5 count it will keep the plate cooler and does not hurt the quality it also doesnt need to be wet only damp ,then tap off the spru gently and you will have a smooth shinny base . another thing I have found is that if you tap the plate up away from the mould it tears the base but if you tap it to keep the plate against the mould body it cuts it way smoother
some times you have a tendancy to cut the spru with the mould sideways so as to get the spru in the box
hope this helps ................Dean

Tasmanian Rebel · Post by **Tasmanian Rebel** » Sun May 30, 2004 10:20 pm

Smoke eater, I thought of another thing that MAY help. For whatever reason, my sprues got better when I started using a heavy welding glove on my right hand and just pushing the sprue plate while exerting slightly downward pressure on the plate. I use a better fitting lighter glove on my left hand to do things that require greater dexterity. The welding glove is nothing fancy-just heavy double layered leather. You may want to try this.

ffffgdave@yahoo.com · Sun May 30, 2004 10:55 pm

the problem sounds like your sprue is solidifying before the bullet.. the pot also may not have enough pressure to force the lead in fast enough or hot enough to get all the air out.keep the pot full, put the mold closser to the spout, if you press agains the spout the lead will be under pressure and you can get fins.if your using a dipper put it right on the spru plate.. im rambling becouse i cant remember exactly what i do to fix this but it is in this area.. i cast 400 grain round balls and its tough to keep them from getting voids.. mould must be hot eoungh not coldish,, i let the lead pour onto the mould for a bit after it is full to let the air work out, pot must be full, puddle should be deep on top of spur plate for plenty of heat in spru to maintain so it can draw down molten lead as it hardens, hold mould level so spru dont run off.. a deep puddle is a major key here and more pressure in the pour. let the pour run a half second before you put the mould under this clears the crap from the spout that comes out first sometimes.. oil on the botom of the spru plate can caouse all kinds of problems, if you oil the mould make sure you clean all of the parts of the mould that are inside and bottom of spru plate and top of mould.. if you add lead to the pot it takes a while to get the lead to heat up, and the mould will cool off. you may have to heat up mould and pot by casting for a while.. so wieght our bullets to make sure their are not voids..shoot them in groups of same weight and same temperature and see wht shoots best.. it will not be a big difference unles a big void of center and shooting long range. good luck dave..