Minié ball casting results

[kh54]

I have some questions for y'all about casting Minié balls but I want to give you some background first. OK, I didn't exactly cast Minié balls but let's just call them that.

I have two Miroku Springfields, an 1861 and an 1863. I've slugged both barrels and got the same size: .5835 land-to-land. I had to hunt for a mold that would give me larger than normal Minié balls and lucked out with a Rapine 583455 mold, and according to the old Rapine catalogue this casts an "International" style ball. (The difference between this and almost all other traditional style Minié balls that I've cast or seen elsewhere is that the top driving band has a shoulder rather than transition directly into the ogive. If anyone has any idea why Rapine or anyone else did this I'm curious to know. And let me know if I've got the terminology wrong, as well - I'm not a bullet guy.) As the Rapine catalogue number implies, this mold is supposed to cast a .583 diameter, 455 grain ball. The reason for this thread is that my results vary, and since I've never been taught or coached on how to cast lead except on Youtube and a lot of reading, I would like to know if my experience is normal, and if not, what I need to change.

Tonight I cast 93 bullets that looked good enough to keep for final winnowing. I measured the diameters of a few bullets; the average is indeed .583, with a range from .5825 to .5845. I will lube and size the keepers anyway, so I figure the diameters are good. (Correct?) They range in weight from 460 to 470 grains, as follows:

460 - 4​

461 - 8​

462 - 8​

463 - 11​

464 - 15​

465 - 25​

466 - 6​

467 - 8​

468 - 3​

469 - 3​

470 - 2​

​

I usually avoid more than a .003 spread in the weight of the bullets that I select for shooting, and I usually select the weight with the most bullets for keepers, 25 at 465 grains in this case. I also keep the two weights on either side, so 15 at 464 and 6 at 466, for a total of 46 usable bullets. 46/93=49 percent.

Soooooo, questions for y'all: How is my methodology? I usually end up with somewhere between 40 and 50 percent of usable Minié balls in any casting session, regardless of the size and mold. Are my results "normal"? What do I need to do to get a smaller range in bullet weights and have more usable bullets from the time I spend casting lead, or is that even likely/possible?

All comments, suggestions, complaints, criticisms, etc. are welcome. Well, most, anyway. And thanks for reading!

 

[ZUG]

I got three CW rifled muskets (repoes) and they measure from 0.579" to 0.582" bore diameter. I have a Lyman Minie ball mold and it throws a 0.580" diameter Minie 95% of the time. I made two sizer that will size my as cast Minie's to 0.577" and 0.580" and true up and round the tail end of the Minie. I am not that concerned about the weight of the Minie but more concerned about its roundness. So far they shoot good enough for me with 60 gr of 2F Goex. My shooting distance is mostly less than 75 yards.

 

[northernThaiguy]

How did you make your sizers?

 

[ZUG]

I made them out of Nylon. Like I said I only have to true up the skirts and the lead is pure lead which conforms to the sizer very easily.

 

[dave951]

I cast minies a bit large for the rifle in question and then use sizers to insure size and correct diameter. All this AFTER I've weighed them. Since I shoot competition, I really care about accuracy and there's a bunch of variables that go into that and weight, diameter and size consistency are critical.

 

[tjiann]

I use +/- 1% in weight as my basis for keepers. So on your list I would probably not have tossed anything. That's a good cast in my opinion.