lymans 58 minie 577611 ?

[charger 1]

I keep hearing what a bugger this thing is to cast. Before I even start down the road of frustration I was wondering about a smidge of tin. A small amount shouldnt effect anything more than flowability should it?

[Buckshot]

..............Not more then a smidge or RCH will impart much hardening. The Lyman 577611 has no special hold on casting difficulty. Most any hollow cavity slug can be frustrating, and Minie' bullet especially due to the extrodinary size of the intruding base core pin, and the comparative thinness of the skirt.

A couple things have worked really well for me when casting a Minie'. First is to simply crank the temp control to warp factor 10, or however high your pot will go. My Lee 20# will maintain about 950* if kept a bit more then half full. One lb ingots pre-heating on the rim and dropped in as needed will drop the temp about 20* or so, but recovers quickly.

Next, if the base plug is pointy I'll file a flat on it so it's about 1/8" across. It seems to help eliminate voids above it.

Next is to have a good solid stream of alloy. Along with that I tilt the blocks a bit so the strean hits the edge of the sprueplate hole until almost full then turn it back straight up. No, you really cannot see the cavity fill. Casting a few will give yuo a good idea of the timeframe, and shortly you won't even think about it as muscle memory takes over.

I believe that allowing the alloy to swirl in off the sprueplate helps agitate the alloy to get a good filled out skirt and to swirl around the base plug. When the cavity comes up full you'll see the alloy 'bounce' up. Continue to pour so as to create a good puddle above the spruehole so the lead in the cavity may draw from it as it cools.

A sprue puddle that is large around but flat does no good. It must have some good useable depth to it. This is very difficult with the Lee Minie' moulds due to the 1/8" thick SP. Best you can do is to run your casting as fast as possible to keep the blocks hot. When you dump one immediately refill, and while the sprue is setting up, roll the just dropped Minie' around so you can look in the base. If you can see a void toss it back into the pot. Running the pot hot and the mould as quick as possible you should get 85% or better visually perfect Minie' boolits.

It is possible that a thin skin of lead can form over the basepin and hide a void. Weighing will tell.

............Buckshot