View Full Version : 58 Cal Minnie balls a PITA
11-30-2006, 06:25 PM
Started casting 58 caliber Minnie balls today for F-I-Ls newly acquired Enfield Rifle/musket repro. Bought it yesterday and bought a Lee mold because it's an hour drive to the ONLY place to buy 58cal ANYTHING.
Anyway, this is my first attempt at Minnie balls, I cast RBs for myself using a Lee mold. This Minnie mold has a pin to form the hollow base, and is a nose pour (single cavity of course). FWIW, the sprue cutter design is different than on any Lee mold I have used before, very short and has a flange (for lack of a better description) to hit with the sprue cutter.
This mold is a pain to get good boolits with. My first attempt ran about 40% rejection rate!! I finally got it down to about 25%, but that's still a lot to me. I cleaned/degreased the mold before I started, I'm using pure (as far as I know) lead, I smoked the mold and am running it fairly hot. Most of my rejects are rinkled or improperly filled out bases. Sometimes the mold doesn't close far enough and I get "fins". I've not had any problems with Lee RB or REAL molds before. Is there a trick to getting good Minnies? Do I just need to be patient and refine my technique? I'll get a good boolit, and then the next one out of the mold is a reject, that's why I think it's technique. Is there something to do with the base plug?
BTW, these 500gr boolits take a DRINK from the lead pot LOL!! Espescially when you're used to casting 158gr boolits (358156) LOL!!!
All input appreciated.
11-30-2006, 06:32 PM
Sounds like you need more heat for the lead and you need the mold hotter.
11-30-2006, 06:36 PM
you need some way to get the pin hotter. It is acting as a heat sink right now, and is cooling the melt too quickly. May want to put it on a hot plate to keep hot, or have a propane torch on low, to get it up to heat. Try casting faster, once you start getting good bullets, and you may not need to heat the pin.
11-30-2006, 06:48 PM
Thanks for the quick replies.
I'm running my pot (a Lee electric dedicated to pure lead) as hot as she'll go. I'll look into keeping the base pin hotter. I've been casting these boolits in rotation with my RB mold, maybe I'm letting the Minnie mold cool too much while filling the RB mold. I'll try again tomorrow using just the Minnie mold.
Thanks again for the replies.
11-30-2006, 07:06 PM
It's a big heavy bullet mould and uses allot of lead. Sounds like you are letting it cool too much. Use it by itself without rotation and you should start putting out some good bullets! I have had a little more trouble with my .58 than other bullets but once it gets going I have little problems. Make sure you preheat the mould good!
11-30-2006, 08:38 PM
add a bit of tin to the melt, it will make a huge difference. I was attempting to cast lee's REAL bullets with some pure lead with little succcess, added some 50/50 solder to the melt and it was like night and day.
12-01-2006, 06:32 AM
Can't add much more than the wise words already spoken here.
I had the same problem with my shotgun slug mold. I THOUGHT I had it hot enough, but it wasn't. Bought a hot plate at the SA and problem solved.
It takes time for the larger bullet molds to warm up and for the bullet to "set", so don't get into a hurry. But do get a "flow" going.
As for the mold not closing up, lube the pivot bolt. You might have to tighten it up or losen it up. Also don't forget to lube the block pins that aid in locking up the mold.
12-01-2006, 07:21 AM
I first started casting with a minne for a repo Italian pipe bomb [zouave] back in 79.I still cast 2000+ minnes a year.They are diffrent and have their own quirks.here is my .02 worth.
Use dead soft lead.That tin will make them look better but they will not expand reliabley and will cause keyholes and flyers.
Cast HOT.Keep the lead hot I run my 20lb Lee wide open when full.The temp will climb as the lead level drops.You could dial back then or just refill the pot.I let the melted lead soak for for 1/2 hour at least before I start casting.[lets temp get even?]
Got to watch the sprue spill over does not run between the handles at the piviot bolt.It gets under the core pin holder is a pain to dig out. Pour fast and let the mould set before dumping the round.This let the minne pull the extra lead it needs when cooling from the sprue.I cast using two moulds. Set one down,pour
2nd,dump 1st and repour...
I have also found that when dipping I get the lowest reject rate with 400 gr moulds on up. On a good day I can run 5% rejects,Bad day 20%.Using the bottom pour 50% is about what I get. I am rather fussy on them though
One thing that has to be prefect is the skirt and cavity.Any wrinkles or voids of any kind goes back into the pot.On a thin skirt such as all the Lees minne moulds it is a weak spot.At best you may get a flyer.worst is a blown skirt.
12-01-2006, 02:07 PM
Those big base pin molds need to be kept going, very hard to use two molds and keep the pin hot. I have used a bunch of them and some would leave an air hole in the bottom of the hollow base and others wouldn't. No amount of air venting changes would fix the problem, neither would casting technique or temperature.
12-01-2006, 06:56 PM
Try some 40 to 1 alloy. Has just enough tin to fill out a mold well, and is only twice as hard as plain lead, with a brinnell hardness of 8.5. :drinks:
12-01-2006, 07:36 PM
I have been casting Minni balls for over 40 years and you want your lead pot and hot as it can get, use a dipper to pour and get your mold hot before you start. I sit it on a hot plate while the lead melts. I use a contact thermometer to make sure its hotter than the lead and start pouring. Pour fast and leave a puddle of lead on top. When the puddle is hard drop the ball and pour again. Lee molds work fine but they are harder to keep up to temperature than the lyman steel ones but I have used both tyes and they make good boolits.
12-01-2006, 08:34 PM
Thanks for all the input. I'm running my pot as hot as it will go, I'm dipper casting and I'm pre-heating my mold on a hotplate. I think my problem is cycling 2 molds.
I'll try again tomorrow, using only the Minnie mold, and try to keep the mold as hot as possible.
Thanks again for all the replies.
12-06-2006, 12:28 AM
..............Yup, all that stuff. Run the pot wide open. Cast as fast as the cooling sprue will let you. Wear a glove and pinch the blocks shut. Be sure the alignment surfaces get lubed every once in awile as this will help them close.
One last thing, and this made a BIG difference in NOT getting voids over the base pin. File a flat about 1/8" across on the tip of the base pin to get rid of the point. If you were getting a void there this mod will cut the incidence in at least half or make it disappear.
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