Minnie ball diameter .575?

60's Refugee · December 12, 2008, 06:01 PM

I have a new Armi Sport .58 Enfield. The bore size is supposed to be .577. Yesterday I bought a new Lee minnie ball mould. It's supposed to be .575. Today I cast up about 60 rounds. After they cooled I tried one for fit in the Enfield. The bullet was so big it wouldn't go in at all! Minnies should be able to fall into the bore on their own weight in a clean gun.

I took a mic and calibrated the ball. Its 1/32" oversized! Is Lee in a habit of this?

I know many of you run your rounds through a sizer. I've never had to do that with a minnie ball.

What gives?

Harry

arcticap · December 13, 2008, 02:00 AM

So the minnie measures .60625?
What kind of lead was used?
The Lee mold is designed for casting with pure lead. If pure lead isn't used the projectile will be larger in diameter because lead alloys aren't as dense as pure lead is.
But if the mold wasn't made to specifications, then Lee should replace it. While I would guess that's not a very common occurrence, it's a distinct possibility.
Could the aluminum Lee mold have gotten too hot during casting which caused it to expand?
Are electronic calipers or a calibrated instrument being used for measuring? How much do the minnies weigh compared to Lee's stated weight for the cast projectile? Are their diameter & weight consistent? More than one minnie should be measured and weighed to see what their average is.
Another possibility is that the bore is undersized and/or also that the "mic" measurement is off.
And there could also be a combination of more than one of the above.

Hawg · December 13, 2008, 05:13 AM

Original Enfield bores were .577. Repros are .580. My Lee cast minies are .578 and my Lyman's are .577. Both load easily. No they shouldn't drop down the bore but the weight of the ramrod pushes mine down to the last three inches or so. I use stick on wheel weights to cast my minies. IMHO you got a bad mold. I have 8 or 9 Lee molds and none of them are so far off that bullets can't be used as cast.

December 12, 2008, 06:01 PM	#1
60's Refugee Member Join Date: September 21, 2008 Location: Galion, Ohio Posts: 34	Minnie ball diameter .575? I have a new Armi Sport .58 Enfield. The bore size is supposed to be .577. Yesterday I bought a new Lee minnie ball mould. It's supposed to be .575. Today I cast up about 60 rounds. After they cooled I tried one for fit in the Enfield. The bullet was so big it wouldn't go in at all! Minnies should be able to fall into the bore on their own weight in a clean gun. I took a mic and calibrated the ball. Its 1/32" oversized! Is Lee in a habit of this? I know many of you run your rounds through a sizer. I've never had to do that with a minnie ball. What gives? Harry

December 13, 2008, 02:00 AM	#2
arcticap Senior Member Join Date: March 15, 2005 Location: Central Connecticut Posts: 3,166	So the minnie measures .60625? What kind of lead was used? The Lee mold is designed for casting with pure lead. If pure lead isn't used the projectile will be larger in diameter because lead alloys aren't as dense as pure lead is. But if the mold wasn't made to specifications, then Lee should replace it. While I would guess that's not a very common occurrence, it's a distinct possibility. Could the aluminum Lee mold have gotten too hot during casting which caused it to expand? Are electronic calipers or a calibrated instrument being used for measuring? How much do the minnies weigh compared to Lee's stated weight for the cast projectile? Are their diameter & weight consistent? More than one minnie should be measured and weighed to see what their average is. Another possibility is that the bore is undersized and/or also that the "mic" measurement is off. And there could also be a combination of more than one of the above. Last edited by arcticap; December 14, 2008 at 02:06 AM.

December 13, 2008, 05:13 AM	#3
Hawg Senior Member Join Date: September 8, 2007 Location: Mississippi Posts: 16,188	Original Enfield bores were .577. Repros are .580. My Lee cast minies are .578 and my Lyman's are .577. Both load easily. No they shouldn't drop down the bore but the weight of the ramrod pushes mine down to the last three inches or so. I use stick on wheel weights to cast my minies. IMHO you got a bad mold. I have 8 or 9 Lee molds and none of them are so far off that bullets can't be used as cast.