First try making cores

[customcutter]

Well I finally tried making cores today. I made an 8 cavity mold last year and ordered a Lee 4-20 pot. I smoked the mold and scratched some air bleeds on each cavity today. I was able to easily reach 6 of the 8 cavities, and poured each of them. Unfortunately when I tried to cut the sprues off I broke the small brass hinge, so I had to stop. I'll be adding a pair of lee mold handles as soon as I can figure out how too, also need to install some alignment pins. Any way I just weighed the 6 cores that I managed to make. 1 was 42.3 gr, 4 were 42.2, and 1 was 42.5. I think the heavy one was due to the sprue cutting off improperly because of the broken hinge. I think I'll make them a little deeper, so that I'll be around 48-50 grains, for making 55 gr projectiles.

I had to make cores because I've finished the core bleeding die. Now I'm working on the core seating die, it is measuring .222 and I need to seat some cores to know how much more to polish the die.:p

[IllinoisCoyoteHunter]

It can be really hard to cut 8 or more sprues at once. Make sure the mold is HOT before casting. Also, the size of the sprue hole makes a difference too. The smallest you can make it to where it fills the cavities is the best.

[customcutter]

It can be really hard to cut 8 or more sprues at once. Make sure the mold is HOT before casting. Also, the size of the sprue hole makes a difference too. The smallest you can make it to where it fills the cavities is the best.

I think the sprue holes are as large as the cores, so I learned that lesson the hard way. Also the small cheap brass hinge was a huge waste of time and effort. Hopefully the Lee handles will solve most of the problem.

[IllinoisCoyoteHunter]

I think the sprue holes are as large as the cores

Yikes! I bet that was hard to cut! Can you recut the sprue plate with smaller holes? Lee does make 6 cavity blank molds that cane be drilled for cores.

[customcutter]

Yikes! I bet that was hard to cut! Can you recut the sprue plate with smaller holes? Lee does make 6 cavity blank molds that cane be drilled for cores.

Yes, I don't know why but I was thinking the hot lead would cut like butter. NOT!!!!

I made the sprue cutter from half of an old mower blade. Unfortunately I didn't bother to aneal it and the only think that would cut it was a 1/2" carbide ball mill. I'm not sure I didn't dull the ball mill doing it. Need to learn those speeds and feed rates, it's getting costly. I've got the other half that I was saving for the .375" cores, and I guess I could sharpen up a spade carbide bit and drill smaller holes in the other half blade.

I just finished milling some slots in the .185" core mold to attach the Lee handles, now I've just got to figure out how to transfer the hole location from the handles to the mold. Also I've looked all over the shop for some 1/4" ball bearings I ordered last year for using as location pins on the molds. Can't find them any where.[smilie=b:

[customcutter]

Sorry double post

[tiger762]

If I may offer a suggestion, cast without the sprue plate. Eyeball the top of the cavity, and stop when you're close. Cores for 22 are easy to swage down to desired weight. If you end up with weights that are all over the map, no problem. It's a tradeoff between: low speed + more moving parts + breaking the sprue to get consistent core weight versus high speed + fewer moving parts with more variability. I wouldn't suggest this for a difficult core like ones for 45cal. The small diameter of 22cal cores (around 0.19") I could even swage wheel weight...

[customcutter]

If I may offer a suggestion, cast without the sprue plate. Eyeball the top of the cavity, and stop when you're close. ...

Hadn't thought about that. The cores now are about .4 or .5 inches long. I could drill out the cavities to about .75" and just stop early before over running the lead onto the mold. All of the cores need to be "sized" in the core die anyway.

Sounds like a winner.

Thanks,
CC

[tiger762]

That's a big 10-4 there, friend. If I were to make a mold to cast up some 22cal cores, I'd drill 'em on half inch centers and make a 10+ core mold in the process. That way, the heat from the cores will be concentrated and you won't end up with cold spots in the mold. I've found that with small weight projectiles like 90 grain 380, I have to fill the mold front to back, then back to front, then front to back, 'cuz there's too much mold (aluminum) with too much cooling surface area and not enough molten lead. Just something else to think about...

[IllinoisCoyoteHunter]

If you overflow the cavity just use wire cutters to cut the core from the extra lead.

[customcutter]

Yes, it's already an 8 core mold. I could probably fit a couple more in. I've milled the slots for the Lee 6 cavity handles, and am getting ready to mount them. Looking at the tips of the handles it appears that there is a slight relief angle right at the mounting pins. It appears that the handles are made so that the half mold can swivel slightly for proper alignment if needed. Is this correct or are the handles solidly mounted. I posted in the mold design and mtc section but haven't gotten a reply. I guess they are mounted with screws???

[pertnear]

I'm just thinking out load here since I've never cast my cores. How tall is the Lee mold? Could you drill almost all the way through then cut your cores from the "lead-wire" you were making? I know its an extra step, but you'd have better control of the core weights with cutting.

FWIW????

[customcutter]

I took the sprue cutter off, it was a waste of time, took too much effort, and finally stripped the threads out of the aluminum.

I thought about drilling the mold holes deeper, and cutting the "wire" twice. That may also help control the temp on the mold better. I'm starting to think that casting much larger ignots and making a die to extrude .185 wire with a 20 ton HF press then use a wire cutter may be much quicker and easier than casting cores, cutting, and finally swaging to final weight. But, then wheres the fun in that and how am I going to learn to use my equipment.