Sizing Miniés?

[kh54]

How much would be too much, if at all, to size down a Minié ball? For example, is it OK to reduce the size by say four or five thousandths and still retain the essential characteristics (shape, uniformity, cannelure depth, etc.)? I have a Rapine 583-455 mold that drops a .581 Minié that I use in a couple of Mirokus, an 1861 Springfield and an 1863 Springfield. (bore size .583). I've been sizing to .579 but they get a bit tight with fouling. I want to try .577 or even .576 and I'm wondering if that would be too much sizing.

I'm planning on ordering a new Moose Mould and I don't want to be wrong about the size for use in an 1858 Parker Hale (bore size .577), so I'm wondering which to buy of the three sizes they offer in the Old Style Hollow Base, 575-450OS, 578-450OS, or 580-450OS. If their mold size is reliable, then I think the 575 should be just right and I can run it through the sizer just to lube it. I haven't been able to reach anyone there to answer these questions - does anyone here have experience or otherwise know?

Any insight that y'all can give me will be appreciated.

 

[TFoley]

You really will have to measure the bore - from my own experience, and from reading the many posts here, the bore can vary anything from .578 up to 590 - and anything in between.

Whatever you get as a measurement, allow between 0.0020 to 0.0035 undersize for the bullet in order to have easy loading and useful skirt expansion.

 

[kh54]

@TFoley, thanks for the response, but with respect, I am beyond that exercise and really I'm just wondering how much re-sizing would deform the ball too much before it makes sense just to buy a smaller mold. It's an issue for me because I don't want to have to buy too many molds at today's prices. (Moose Moulds is asking $150 plus shipping for a single cavity OS mold.)

I also have five different "58" caliber muskets, all with different bore sizes. I really don't want to have to purchase five different molds. Maybe two...

 

[hawkeye2]

It would take a lot of effort to size a mini from .581" to .576" and it ought to be done in 2 stages using 2 different dies. If done carefully it shouldn't deform the mini but it will drastically reduce the size of the grease grooves. Going from .581" to .578" is doable in one step but .003" is about all I would do at a time.

TFoley has posted excellent advise and I would basically say the same thing. If you don't want to measure I would suggest the .578" mold as you can easily size it down to .575" and it's just possible it might work as is. BTW balance the cost of a mold against 2 or 3 sizers.

 

[ord sgt]

I have a mold that casts a .575 minie, which I force through a .575 sizer for uniformity. This loads and shoots very well out of my P-H Enfield. Many clay birds and tiles have been broken with this bullet.

 

[dave951]

You can easily size down .005 with no issues on the bullet you've mentioned. Past that, you may be better off getting a mold that is closer to your bore. I shoot the RCBS Hogdon in two rifles, one is 580 and the other 576. My mold drops at 580 and I shoot as cast in one gun and size to 575 for the other which BTW is a 2moa gun.

Sizing swages the grease groove on the bullet and reduces them in size so they don't carry as much lube. In the case of the Trashcan, don't think of sizing more than .001 as those iddy biddy grooves will go away quickly.

Moose molds drop darn close to the size he says if you use pure lead. I wouldn't hesitate to order from him.

You mentioned a problem with the bullets getting tight from fouling with guns that measure 583 and a bullet that's 581. In my experience, you have a problem that needs to be solved. You should have no issues with a bullet .002 under bore size for multiple shots if the lube and powder are in balance. Minies are a balancing act get one thing wrong and fouling rears it's ugly head. I ran my Parker Hales once in practice just to see how far my loading can go and I'm not losing accuracy nor having fouling problems for 20+ shots. In our work doing instruction with kids, I ran a Zouave once for over 60+ shots straight without wiping and accuracy was still sufficient for a kid to blow the chains off of two gongs at 50yd.

So the question is, what powder, caps, and lube are you using? And the answer to your initial question is yes, you can size "usually" .005 without issues, depends on the design of the bullet.

 

[kh54]

You mentioned a problem with the bullets getting tight from fouling with guns that measure 583 and a bullet that's 581. In my experience, you have a problem that needs to be solved.

Thanks Dave. After that post I began wondering about that myself. I may have confused bullets and now I need to cast more and get back to the range, hopefully next week. Thanks for the tip.

 

[toot]

I have allways shot MINNIES / HOLLOW BASED bullets as cast / dropped. I ain't adding another process to the equation. if it ain't broke don't fix it!. jmho.

 

[45man]

How much would be too much, if at all, to size down a Minié ball? For example, is it OK to reduce the size by say four or five thousandths and still retain the essential characteristics (shape, uniformity, cannelure depth, etc.)? I have a Rapine 583-455 mold that drops a .581 Minié that I use in a couple of Mirokus, an 1861 Springfield and an 1863 Springfield. (bore size .583). I've been sizing to .579 but they get a bit tight with fouling. I want to try .577 or even .576 and I'm wondering if that would be too much sizing.

I'm planning on ordering a new Moose Mould and I don't want to be wrong about the size for use in an 1858 Parker Hale (bore size .577), so I'm wondering which to buy of the three sizes they offer in the Old Style Hollow Base, 575-450OS, 578-450OS, or 580-450OS. If their mold size is reliable, then I think the 575 should be just right and I can run it through the sizer just to lube it. I haven't been able to reach anyone there to answer these questions - does anyone here have experience or otherwise know?

Any insight that y'all can give me will be appreciated.

If the ball is the same as the bore, do not size, it is perfect. For the Parker, Get.578 and size to .577. We learned long ago a Minie" should be bore size. It will expand into the grooves.