Bullets narrow in middle

[Charlie Two Tracks]

I have a TL-358-wc mould. It is the tumble lube design. I am just starting to cast and this is a new 2 cavity mould. I poured 250 of them today and thought that I was doing a good job. I just went and measured them. The ends measure .358 but the center of the boolits are narrower. Sometimes they will measure .352 and vary. Is this the nature of the beast or am I doing something wrong? I smoked the mould and they release fairly easy.

[buck1]

cast hard and fast untill they come out frosted. then check them. This will tell you if its truely under sized or not.

[Chamfered]

I think I have the same style mold, DEWC tumble lubed. I have it in 6 cavity and just sorted them by looks. I know its not real scientific but I just pitched the ones that did not look good. Loaded the rest with 2.7 gr Bullseyes and ran them through a Dan Wesson at 33ft. Shot about 1 inch off hand, which isn't bad considering its my hand. I used Lees Alox cut with 10% mineral spirits. I only ran about 12 through it to verify that it was going to shoot good enough for my indoor range. After reading your post I am going out and measure mine on the ends. 352 seems like a pretty big delta, but I think you should size and lube a couple and see how they print.

[SciFiJim]

Smoking the mold might be part of the problem. You really shouldn't need to smoke it to get the boolits to fall out. Do a search for "Leementing". I think it is one of the stickies.

You might also be getting some "shrunken band syndrome". This occurs when the ends of the mold are cooler than the middle and the ends of the boolit solidify first. As lead cools and solidifies, it shrinks. This is indicated by the dimple that occurs in the sprue while it is cooling. That is caused be the boolit drawing more liquid as it cools. If the end by the sprue plate freezes before the middle, there is no place for the boolit to draw from and the middle will pull in. Shrunken band syndrome could be an indication of the alloy too hot or the mold and sprue plate too cool or both. You have to find the balance.

When using aluminum molds, you generally have to run your alloy at a higher temp than you would with an iron mold. Aluminum cools quicker and requires more heat from the alloy to stay hot than an iron mold. This does not mean that you run the temp as high as you can get it! Just hot enough to get consistent good fill out is what you are looking for.

As a test, make sure your mold is preheated and start casting as soon as the melt is liquid enough to pour. Continue heating the melt to raise the temperature and continue casting. You will observe a range that works best for that particular mold. If you have a thermometer, watch for the temp that works best and make a note of it.

[Charlie Two Tracks]

Thanks guys. I will try your suggestions. I want to do this right.

[462]

Charlie,
In addition to the above mentioned "Leementing" process and casting at a higher temperature, apply Kroil to the mould cavities -- it will allow the boolits to almost FALL out of the mould. http://castboolits.gunloads.com/showthread.php?t=61126

I've found that Lee moulds require the thermostat to be turned up all the way until the boolits begin to drop frosty, as SciFiJim said. At that point, turn the thermostat down -- one number at a time -- until the frosting disappears. Over time, you will know which number to turn it to. By the way, there is nothing wrong with frosty boolits.

There is no need to smoke a mould

Unfortunately, moulds require a bit of TLC before they work at their optimum potential.

[mdi]

Sounds to me like you're doing it right. What are you measuring with? Most don't use calipers to measure boolits with because of the narrow blades. Micrometers more accurate.

[stang68]

I also have a Lee 2 cavity TL .358-.158 SWC mold and after having some problems I Lee-mented the mold and then re-smoked it pretty heavily. After the smoking I was dropping boolits that were .356 dia. in the middle. I then Lee-mented again and this time did not smoke the mold and the boolits were back to the correct size. Don't know for sure if the smoking caused the problem or if it was just coincidental and caused by something else.

[462]

Smoking a mould decreases cavity diameter.

[Charlie Two Tracks]

So if I am understanding the Leementing process, it is spinning a boolit in the mould. How do you do that if you don't have a good one to start with? I am not giving up. I will keep at this until I figure it out. The ones I did today are a little bit better but still narrow in the middle.

I just found the sticky about Lee-Menting. There is a lot more than I thought. I will get to work on it.

[462]

Charlie,
Tooth paste or Bon-Ami, applied with a tooth brush, are very mild abrasives that will remove any hanging chads and get into all the nooks and cranies, and will not damage the mould. Wash with Dawn dishsoap and HOT water. Follow up with spray brake parts cleaner.

I think that once the mould is thoroughly cleaned and the thermostat cranked all the way up, you'll be okay.

Don't forget the Kroil to aid boolit drop.

Are you having fun, yet?

[Charlie Two Tracks]

I am having fun 462. It's strange but even if I get frustrated for awhile, the urge to go back is still there. Kind of like golf, fishing or anyother hobby. I do appreciate the help. Thanks guys. I seriously doubt this is my last question.

[Charlie Two Tracks]

So, I got up early this morning and tried again. After Lee-menting the mould and turning up the heat to 700 deg. it seems to be working better. I should re-phrase that. The mould dropped two perfectly good boolits. The other 20 had something wrong with them. I have to get used to holding the mould level and pouring at the same rate. I am using a Lee bottom pour and if the mould is too far down, it spatters the lead out of the mould. I also didn't pay attention to how the mould was closing and got a few where the lines were not lined up. I'll just have to keep practicing. I don't believe it is the moulds problem and since I can't blame anyone else, it must be me. The boolist drop out quite easily now.

[mdi]

Does your Lee pot have a mold rest? If so set the mold on that when you drop in the lead. Adjust it to the hieght that works best for you so the pour is the same every time.

[462]

Charlie,
You've made substantial progress.

You will find that varying the distance from the mould to the spout will have an effect on fill out...usually the closer the better. Some people "pressure cast", in which the mould is held directly to the spout, others hold the mould close to the spout and when the cavities are full press it to the spout. Some moulds like to have the cavities filled individually, while others prefer a continuous flow which results in one big sprue, rather than two.

Lee moulds have a nasty habit of not aligning properly, when being closed. A simple trick is to set the bottom of the mould on a flat surface, then close it.

Also, make sure that the sprue has sufficiently hardened before swinging the plate. You will see the sprue suck down, leaving a dimple indicating that the cavity has filled.

Each mould will have its unque characteristics, and by reading it and the resulting boolits, you will learn them. Sometimes, it's like reading Sanskrit, though. After you've learned what a mould likes, you may want to make notations for future reference.

[stang68]

You might also want to re-read the instructions from Lee that came with your mold or bottom pour spout. Lee recommends that you tilt the mold when filling rather than aiming the stream straight into the cavity. Doing that seems to have solved my problem with bad boolits.

[Charlie Two Tracks]

You guys have given great advice. This afternoon I was able to pour 500 great looking boolits. Before I started, I did the Lee-menting to the mould again. The boolits drop right out. I have the temp. at 750 and the mould about 1/2 inch from the spout. Couldn't have done it without ya. thanks again.

[462]

Charlie,
Good going, got the mould and temperature right. Ain't it great, and doesn't this site have the best and most helpful members?

Onward!