Casting questions

[DemolitionMan]

Hi all,

I've been reloading for a while but recently decided to take the plunge and start casting my own bullets. I am currently doing 45 ACP but plan to do 38 in the near future.

I've now done two sessions of casting and I have a few questions that I thought the forum might be able to answer.

First, I am sometimes getting what look like fine lines or wrinkles in the cast bullets. Often when this happens the grooves at the base of the bullet do not look as defined as they should. I've been reading a few things online that suggest this may be due to the metal cooling too quickly. Does that sound right, and if so should I therefore be casting at a higher temperature?

Second, I am consistently getting bullets that are 4-9 grains heavier than the 230 grains that it the mold should produce. I suspect it may have to do with the metal. The lead I am using is actually reclaimed metal from a shooting range. (Aszerigan from Profire sells ingots of it at a very good price, btw). Since it is not pure lead, my guess is that it is slightly more dense and therefore I'm getting heavier loads. Does that make sense, or is there something else going on?

Finally, I have to tell on myself. I'm a gadget guy so I tried to make sure I got every little item needed for casting. I laid it all out and looked the pieces over cold before ever trying to melt lead. Melting pot? Check. Mold? Check. Handles? Check...etc, etc.

I remember looking at the aluminum block mold and wondering "What are these two screws on the sides? They don't seem to do anything." I'm sure experienced casters are already shaking their heads, but it didn't occur to me until I was partway through my second session and had dropped half of the mold on my workbench: "Hey, there are two holes in the tips of the mold handles. I wonder what those are for....oh."

Yeah, I can be that clueless sometimes. Of course the mold was already hot so I will have to wait until everything cools down before I can put the screws in the mold through the holes in the handle tips.

In my defense, it does not say anything about doing that in the mold instructions, and there were no instructions with the handles. OTH, it probably was obvious to every other person who ever bought the two items....but just in case it wasn't, now you know what those screws are for.

 

[6birds]

First, I am sometimes getting what look like fine lines or wrinkles in the cast bullets. Often when this happens the grooves at the base of the bullet do not look as defined as they should. I've been reading a few things online that suggest this may be due to the metal cooling too quickly. Does that sound right, and if so should I therefore be casting at a higher temperature? It might be your mold is too cool, keep it hot between pours, and should get better results. I have an electric iron that I keep in the mold to keep it hot.

Second, I am consistently getting bullets that are 4-9 grains heavier than the 230 grains that it the mold should produce. I suspect it may have to do with the metal. The lead I am using is actually reclaimed metal from a shooting range. (Aszerigan from Profire sells ingots of it at a very good price, btw). Since it is not pure lead, my guess is that it is slightly more dense and therefore I'm getting heavier loads. Does that make sense, or is there something else going on? Alloy differences, don't sweat it.

When you have some free time, google CASTBOOLITS, and enjoy.

 

[ANeat]

First your wrinkles could be either some residual oil in the mold, brake cleaner is something handy to clean them with.

Or the mold is not getting hot enough, you can either turnup the heat on the pot a little (approx 700 degrees is a good starting point)
Or cast at a faster pace.
Preheating the mold on a hotplate can help speed things up but if you dont have that option just start casting and your first several pours can just go back into the pot till the fill out.

Your bullets being heavier than the mold design just indicates your alloy is probably a little more "lead" %. Most molds are based on 92% lead, 6% antimony and 2% tin. Go off that and your bullets can be heavier or lighter by several grains, no big deal really.

The only thing you need to watch is your bullet size, as you get closer to pure lead the bullets cast smaller in diameter, pure lead shrinks more. So if say you want a .452 bullet and your mix is closer to pure there is a chance you coule get a .451 bullet. And if that is too small for your guns barrel lead bullets that are too small tend to lead the barrel and shoot very poorly. Just something to keep an eye on.

 

[DemolitionMan]

Thanks for the quick replies!

It might be your mold is too cool, keep it hot between pours, and should get better results. I have an electric iron that I keep in the mold to keep it hot.

I had followed the directions to heat the mold by laying it on top of the pot, but maybe that wasn't good enough. I believe that the wrinkles were more frequent in earlier rounds of casting, which would be when the mold was cooler. I'll have to think about how to get it hotter prior to casting.

When you have some free time, google CASTBOOLITS, and enjoy.

I recall someone else mentoning that site; I'll have to check it out.

First your wrinkles could be either some residual oil in the mold, brake cleaner is something handy to clean them with.

I cleaned them with WD-40 and a cotton swab. I have some brake cleaner around I could try. I've cast about 120 bullets now in a 6 bullet mold; hopefully any residual is gone.

Or the mold is not getting hot enough, you can either turnup the heat on the pot a little (approx 700 degrees is a good starting point)
Or cast at a faster pace.

I think I'm casting pretty quickly, though I'm wondering if I should increase the flow rate. It takes about 2 seconds to fill a chamber in the mold right now. If that is too long it could explain some things.

I am concerned about temperature. My pot is a Lee and just has numbers on a dial. Is there somewhere around town to get a high-temperature thermometer? I could always go with the infrared sensors, I've always wanted an excuse to buy one of those!

Your bullets being heavier than the mold design just indicates your alloy is probably a little more "lead" %. Most molds are based on 92% lead, 6% antimony and 2% tin. Go off that and your bullets can be heavier or lighter by several grains, no big deal really.

That's sounds like the sort of thing I was suspecting. I'm a little concerned just because I'd like to be able to create more consistent rounds.

The only thing you need to watch is your bullet size, as you get closer to pure lead the bullets cast smaller in diameter, pure lead shrinks more. So if say you want a .452 bullet and your mix is closer to pure there is a chance you coule get a .451 bullet. And if that is too small for your guns barrel lead bullets that are too small tend to lead the barrel and shoot very poorly. Just something to keep an eye on.

Thanks for the tip. I ran a number of them through a sizer and had very little resistance or evidence of sizing on the bullets. I'm going to check the results with my micrometer later, esp. comparing unsized to sized.

 

[ANeat]

WD40 wont cut it, and dont just expect it to burn off. You want the cavities clean, really squeaky clean.

The oil, or any residue wont allow the lead to fill out properly, and any gassing from the residue will create voids in the bullets.

It shouldnt take more than a second or so on each bullet cavity when pouring/filling, you should have several seconds for the sprue to solidify

Lyman and RCBS make casting thermometers, the infared type wont cut it on a reflective surface like molten lead

 

[zdogk9]

if you don't have brake cleaner, you can take an OLD pot and boil the mold blocks with a couple of drops of detergent added to the water. I capitalized old to bring it to your attention before your wife does. The WD40 will cause the poor fillout every time. Keep the mold hot, move at a right smart pace and you'll be fine.

 

[sbcman]

I agree with the others. A bit hotter temp and faster pour rate might fix the problem. 2 seconds is just about right to have both sides of a double mold filled.

If you're casting outdoors this time of year, your mold will cool more quickly, especially if you use Lee molds like I do. Also, if mixing sprue and new lead back in, give some extra time for everything to get good and hot.

And, I agree with others that the variations your seeing in bullet weight is nothing to worry about. Very common to have that much of a difference in my experience.

 

[Slow Hand]

You've got some good advice so far and I agree with all of it. I personally like to cast hot, I don't have a thermometer (need to buy one) but i cast pretty hot. I, too have a Lee pot, a bottom pour model. When casting with the Lee 6-cavity moulds, it empties out pretty quick, so i just keep it cranked up almost to max as I'm constantly adding ingots. I do set the mould on top of the pot while the lead melts. It helps some, but you will still need to dump the first few pours. i also pre-heat the ingots on top of the pot. Put two of them up there when the pot is full and figure they've warmed up soem by the time they are needed. the Lee moulds are aluminum and heat up faster than steel moulds like Lyman or RCBS. they also cool down faster, so if you stop to count bullets aor look them over, you may need a few pours to get itback up to casting temp. I use a big green bean can to dump my sprues into as I'm casting, then I can pour that scrap back into the pot as it empties out. One last tip on using the six cavity moulds. Not sure if it helps or not, but I alternate pouring from front to rear than rear to front. Figure as I pour all cavities full, if I always do front to rear it will heat up the fornt cavities faster.

Keep at it, it's a fun part of our hobby and you'll enjoy shooting ammo even more when you've cast the bullets yourself!

Doug K

 

[Leadeye]

A thermometer is a big help and don't worry about the difference in weight, alloy can go all over the map. Be sure and check your bore diameter and keep your cast bullets at least .001 over that. This gives best accuracy and least leading.

 

[zdogk9]

Another tip; When you're casting don't obsess over your boolets once you determine that they're coming out OK, there will be plenty of time to cull when you size and/or lube them.