RCBS 500M melt issues

[tucten]

I just received my new RCBS 500M minie mould. It?s been a bugger to make bullets. I moulded 25 before I was able to completely fill the base ring. After I got my lead into the 950 range, and with me tapping the mould it finally started filling, but the lead was so hot I had ?wings? where the molten lead crept between the blocks.
Are there any tips that might help me. 950 degree lead is a tad 10839

[EPPS1919]

I run my lead to 800 to 850 and preheat the mould with a propane torch


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[lostinwestchester]

I never go over 800. But pre-heating the mold is a must. Then you need a good pace. To keep things moving well

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[Carolina Reb]

Since you just got it, I bet it still has some if the preservative grease in the mold cavity. Try cleaning it really well with acetone or alcohol. 800 degrees should do the job when the mold is clean.

[Big Grit]

I'm not sure, but from your picture it looks like the base plug on the mold is too long, causing the skirt to be much to thin.

[Maillemaker]

I agree - something strange is going on with that base plug. Make sure it is fully screwed in place.

I cast around 850-875. Clean mold and preheating is necessary.

I have decided that ladle-pouring is the only way to get consistent results with hollow-cavity bullets. I don't know if it the starting the pour with the mold sideways or simply the speed of the pour that makes it work, but I can tell by weighing bullets that you get much more consistent weights when ladle-pouring than with a bottom-pour spout.

Steve

[MR. GADGET]

Looks like something is off. Post some pictures of the mold and plug.

One thing I had a problem with on a few RCBS molds were the pins. The pins are are rounded and the holes that stick in had a sharp edge. When I called they said use your case debur tool and that will fix it. The mold would not close 100%.

[tucten]

10840
i sure hope that extra thin ring is correct.

[Joseph Plakis Jr, 00302V]

After looking at the photo my first question is did you purchase a used mold. The base plug is too long. The base plug in both of my RCBS molds when you put the base plug in one side of the mold stops at the end of the bullet cavity. I would think using the base plug that you have you stand a good chance of pulling the bottom skirt on the bullet off.
If you have a new mold I would call RCBS to get it replaced or fixed!!
Joe Plakis Jr
Hampton Legion

[tucten]

Heated to 850, clean mold. Without tapping they come out like this.10841

[tucten]

After looking at the photo my first question is did you purchase a used mold. The base plug is too long. The base plug in both of my RCBS molds when you put the base plug in one side of the mold stops at the end of the bullet cavity. I would think using the base plug that you have you stand a good chance of pulling the bottom skirt on the bullet off.
If you have a new mold I would call RCBS to get it replaced or fixed!!
Joe Plakis Jr
Hampton Legion
New mould. I ordered it from Midsouth.

[Carolina Reb]

It sure looks like a base plug issue. Will you be at Statesville next weekend? If so, bring that mold and I'll bring mine for comparison.

[tucten]

See you there!

[Maillemaker]

I agree your base plug is too long. You should not have a step inside the cavity.

Here is what mine looks like:

https://i.imgur.com/m6FZHk1l.jpg
https://i.imgur.com/ObgFoKKl.jpg

Full size pictures here: https://imgur.com/a/vimREku

Steve

[michael noble]

It's obvious that the base plug is too long.

[Lou Lou Lou]

Looks like a couple small washers under the plate might solve the problem w/o machining

[Muley Gil]

Looks like a couple small washers under the plate might solve the problem w/o machining

I think that would make matters worse. Depending on how long it would take to get a replacement, the base of the base plug could be filed down by the OP.

[MR. GADGET]

I would contact RCBS they may just send you a base plug.
It tell you the specific numbers for yours.

[Maillemaker]

I think that would make matters worse. Depending on how long it would take to get a replacement, the base of the base plug could be filed down by the OP.

I think he means to put the washers under the sliding capture bar.

I agree contact RCBS for a new pin. Or, take the mold to a machinist and tell them to mill enough off the bottom of the plug to make it fit. Hopefully the threaded hole is still deep enough at that point for the captive screw to still bottom out.

Steve

[Hal]

RCBS is easy to work with. Give them a call. They will make things right.

[Kevin Tinny]

Hello:

Have had two problems w RCBS minie moulds:

The plate on the bottom has a specific GROUND contact FACE.
It may or may not be marked with an "X".
The ground face is the one that should be against the plug and bottom of the blocks.
On all of mine, if incorrect side against plug, the slide plate screws will not align when blocks closed.

I had two new, unused ones with a plug height issue that located the plug shoulder below the skirt base, unlike yours that located the plug shoulder ABOVE the skirt base.
John Bly saw that during unrelated work to widen the meplat and put a brass shim under the plug.

FWIW, I found a wider meplat casted more uniformly. Smiles.

Kevin Tinny