Muzzleldrs Oversized .58 caliber bore

KHyatt

Corporal
Joined
Jan 7, 2019
I measured the bore of a recently purchased Miroku 1863 Springfield reproduction and found it to be over .58 caliber. I think my methodology was ok but y’all let me know what you think: I slightly hammered a Minie ball to make it mushroom a bit, screwed it to a 5-inch, 1/4-20 bolt and drove it into the muzzle about four inches. When I pulled it out I measured the “slug” to be .585 caliber. I used the same method on my two other muskets. My Armi Sport 61 Springfield measured .581 and my Parker Hale 53 Enfield was spot on at .577.

Questions: (1) Does anyone know if this was common to Miroku reproductions, i.e. to be oversized? (2) Will a .58 Minie work or will it be undersized? (3) If undersized, how do I cast an oversized Minie? (So far I haven’t seen any oversized molds and I’d rather not have to pay the big bucks for a custom mold, if possible.)

I’m really hoping to make the Miroku and the PH accurate, match-grade guns, or at least close to it. Unfortunately, I’m really new to black powder and I’m not in a location where I can easily connect with experienced shooters such as N-SSA members, so I’m forced to become self-taught.

As always, I appreciate thoughts, comments, advice, criticism, etc.

BTW, anyone out there near the Flathead Valley in Montana who would like to connect?
 
I measured the bore of a recently purchased Miroku 1863 Springfield reproduction and found it to be over .58 caliber. I think my methodology was ok but y’all let me know what you think: I slightly hammered a Minie ball to make it mushroom a bit, screwed it to a 5-inch, 1/4-20 bolt and drove it into the muzzle about four inches. When I pulled it out I measured the “slug” to be .585 caliber. I used the same method on my two other muskets. My Armi Sport 61 Springfield measured .581 and my Parker Hale 53 Enfield was spot on at .577.

This method will get you in the ballpark. A pin gauge will be much, much closer. You don't need the whole set, just a couple in the range you're interested in. They're on Amazon individually for like $5 each or a an entire set for about $60. I doubt the Armi is .581 and I'd bet the Parker is actually .575. I also think you might have some muzzle wear on it so that reading may be off quite a bit.

Questions: (1) Does anyone know if this was common to Miroku reproductions, i.e. to be oversized? (2) Will a .58 Minie work or will it be undersized? (3) If undersized, how do I cast an oversized Minie? (So far I haven’t seen any oversized molds and I’d rather not have to pay the big bucks for a custom mold, if possible.)

1)- It's not uncommon for repops to be large.

2)- So say a .58 is to general. You have to know that actual bore size and get minies sized accordingly. A minie undersized by more than about .005 will never shoot well. Things get better as that size approaches the bore size.

3) Get an over sized mold. They make them. I have a couple that drop at .581 that I size to .579 for my 62 Colt Contract with a bore size of .580. Sizing dies are available as well. There are a couple different types. Some like the one designed to fit an arbor press. I like the ones threaded to 7/8x14 to fit a standard reloading press. If you want an oversized mold, post on the N-SSA board and ask if anyone has one to sell. You'd be amazed at what will pop up. RaiderANV is a stand up guy and might be able to help. Before you go to that length, get some sample bullets from - http://www.lodgewood.com/Bullets_c_7.html Be sure to specify size, Pat has a wide range of bullets. We often will buy a sample from Pat before springing for a mold.


I’m really hoping to make the Miroku and the PH accurate, match-grade guns, or at least close to it. Unfortunately, I’m really new to black powder and I’m not in a location where I can easily connect with experienced shooters such as N-SSA members, so I’m forced to become self-taught.

As always, I appreciate thoughts, comments, advice, criticism, etc.

BTW, anyone out there near the Flathead Valley in Montana who would like to connect?

You'll find that the Miroku and PH can be great shooters but be warned, the issue sights are rubbish for "match grade" shooting. You'll probably want a taller front post and an insert for the rear sight base.

Since you're new to BP, avoid the subs at all cost. Shoot only real BP. The fouling is much easier to deal with and you'll have less headaches. I shoot Swiss and Old Eynsford both in 3fg. Old E is a Goex product and is their match grade powder. Get good quality caps. CCI reenactor caps are garbage, RWS or Schutzen are much preferred. Lube- stick to natural materials. Most of us use some form of beeswax + something. That "something" being Crisco, lard, olive oil, lanolin, etc. I've found the best in my PH is beeswax/lard at 50/50.
 
I had the same problem with my Armesport 1853. There are over sized molds available, or there was 14 years ago, that you can find online.
 
Years ago, I bought a replica Zouave but I sold it because the ammo I purchased with it did not fit. The patched Round ball was too tight and sometimes I had to literally hammer it down the bore----a practice that I do not recommend. I guess I could have gotten a thinner patch. And the Minie ball seemed too loose to me. I did not enjoy shooting it so I got rid of it.
 
Did you measure the bore land to land or groove to groove ? The land is the raised portion of the rifling. The groove is just that. This can throw you off a bit. Slugging the bore as you did was a wise move. I'm not sure but I think there are some somewhat oversized Minies available pre-cast. Check with Track of the Wolf on line. Also see what S&S has. I'll do some checking. I recall some of the Italian Zoli mfg. "Zouave" replicas being oversized.
 
Thank you all very much! Some of your tips I knew, others are new to me and I'll be following-up. (BTW, Peter, I knew to only measure the lands.)
 
Thank you all very much! Some of your tips I knew, others are new to me and I'll be following-up. (BTW, Peter, I knew to only measure the lands.)

BTW- I compete in the NSSA and am also a certified NRA Muzzleloading Instructor.
 
Thank you all very much! Some of your tips I knew, others are new to me and I'll be following-up. (BTW, Peter, I knew to only measure the lands.)
Were you going hard core authentic with your bullets ? Wadcutters work well in some bores. (I tried those in a Shiloh brand repro Sharps and they worked fine!) I checked S&S and found some oversized traditional minies as well as wadcutters. Mark DeHaas (I think that's his name) makes repro barrels for CW rifles and muskets. Give him a shout and see what he says. Maybe he knows of a source for molds that won't cost a King's ransom. Share what you find and we all learn
 
Years ago, I bought a replica Zouave but I sold it because the ammo I purchased with it did not fit. The patched Round ball was too tight and sometimes I had to literally hammer it down the bore----a practice that I do not recommend. I guess I could have gotten a thinner patch. And the Minie ball seemed too loose to me. I did not enjoy shooting it so I got rid of it.
I've had to use a .562 diameter round ball and thinner patching to work in a "Zouave". If I remember right I used a Lee mold to cast that size ball. But like you I got rid of the beast. (Bore size seemed to be inconsistent with the various Zouave repros. Some too big and others way small.)
 
This method will get you in the ballpark. A pin gauge will be much, much closer. You don't need the whole set, just a couple in the range you're interested in. They're on Amazon individually for like $5 each or a an entire set for about $60. I doubt the Armi is .581 and I'd bet the Parker is actually .575. I also think you might have some muzzle wear on it so that reading may be off quite a bit.



1)- It's not uncommon for repops to be large.

2)- So say a .58 is to general. You have to know that actual bore size and get minies sized accordingly. A minie undersized by more than about .005 will never shoot well. Things get better as that size approaches the bore size.

3) Get an over sized mold. They make them. I have a couple that drop at .581 that I size to .579 for my 62 Colt Contract with a bore size of .580. Sizing dies are available as well. There are a couple different types. Some like the one designed to fit an arbor press. I like the ones threaded to 7/8x14 to fit a standard reloading press. If you want an oversized mold, post on the N-SSA board and ask if anyone has one to sell. You'd be amazed at what will pop up. RaiderANV is a stand up guy and might be able to help. Before you go to that length, get some sample bullets from - http://www.lodgewood.com/Bullets_c_7.html Be sure to specify size, Pat has a wide range of bullets. We often will buy a sample from Pat before springing for a mold.




You'll find that the Miroku and PH can be great shooters but be warned, the issue sights are rubbish for "match grade" shooting. You'll probably want a taller front post and an insert for the rear sight base.

Since you're new to BP, avoid the subs at all cost. Shoot only real BP. The fouling is much easier to deal with and you'll have less headaches. I shoot Swiss and Old Eynsford both in 3fg. Old E is a Goex product and is their match grade powder. Get good quality caps. CCI reenactor caps are garbage, RWS or Schutzen are much preferred. Lube- stick to natural materials. Most of us use some form of beeswax + something. That "something" being Crisco, lard, olive oil, lanolin, etc. I've found the best in my PH is beeswax/lard at 50/50.
Try a mix of "bag balm" used by farmers who milk cows) with tallow (avoid lard) and bee's wax. I've seen some use cooking oil in the mix along with paraffin. Results were so-so. The current Dixie catalog has the proportions for the bag balm recipe and from what I'm reading it works on black powder AND modern "suppository" guns. I like Olde Eynsford, Swiss, Goex and Shutzen. I still have two or three cans of Curtis and Harvey powder from Scotland! No Pyrodex or other subs for me!
 
Thanks for your input, Peter. I'm not exactly going "hard core authentic" but I do want to try and use something close to a Civil War style Burton/Minie bullet. My first shooting experiments were with my Parker Hale 53 Enfield, and I cast my own bullets with the Lyman 575213-OS. For now, I think I'll still work on the Enfield first before I do much with the Miroku. Unfortunately, an unexpected move last year for work took over my life and I didn't get to shoot much, so I didn't learn much, either. I'm sort of starting over this year.

I used sheep tallow and bee's wax for my lube, but I followed the Ordnance Manual recipe, more wax than tallow (4 to 1 as I recall). I'm going to change that this year and try about half-and-half and see if I get some improvement. I've got everything to start anew, except for drier weather and a place to shoot. I will report on my progress, as you suggested. I'm learning so much from you and all the other kind folks at CWT!

I'm off now to a local machinist to measure the bores of my three muskets. I'm curious to know how accurate my crude slug method was.
 
Try a mix of "bag balm" used by farmers who milk cows) with tallow (avoid lard) and bee's wax. I've seen some use cooking oil in the mix along with paraffin. Results were so-so. The current Dixie catalog has the proportions for the bag balm recipe and from what I'm reading it works on black powder AND modern "suppository" guns. I like Olde Eynsford, Swiss, Goex and Shutzen. I still have two or three cans of Curtis and Harvey powder from Scotland! No Pyrodex or other subs for me!

I checked at our local vet supply. Bag Balm is nothing more than aloe and lanolin. Lard does NOT cause a problem. I've experimented with lard v crisco v olive oil v tallow. Results pretty much depended on the gun. Both my Parker Hales like beeswax/lard best. Musket prefers olive oil. Sharps doesn't seem to care. Smoothbore likes olive oil. In the N-SSA ask 5 skirmishers what's the best lube and get 12 different answers. You just have to experiment and don't take anyone's word as true gospel although I'll still always recommend starting with beeswax/lard initially and go from there.
 
My slugging method gave me the first number in the pairs below and the machinist today measured the bores with a bore gauge for the second number in each pair:

Miroku: .585 .5830​
Armi Sport: .581 .5771​
Parker Hale: .577 .5766​
I think I might have not been paying attention when I measured the Armi Sport; it looks like I measured the grooves and not the lands.
 
Thanks for your input, Peter. I'm not exactly going "hard core authentic" but I do want to try and use something close to a Civil War style Burton/Minie bullet. My first shooting experiments were with my Parker Hale 53 Enfield, and I cast my own bullets with the Lyman 575213-OS. For now, I think I'll still work on the Enfield first before I do much with the Miroku. Unfortunately, an unexpected move last year for work took over my life and I didn't get to shoot much, so I didn't learn much, either. I'm sort of starting over this year.

I used sheep tallow and bee's wax for my lube, but I followed the Ordnance Manual recipe, more wax than tallow (4 to 1 as I recall). I'm going to change that this year and try about half-and-half and see if I get some improvement. I've got everything to start anew, except for drier weather and a place to shoot. I will report on my progress, as you suggested. I'm learning so much from you and all the other kind folks at CWT!

I'm off now to a local machinist to measure the bores of my three muskets. I'm curious to know how accurate my crude slug method was.
Evidently the ordinance department used bayberry wax for a time. At least they did during the "trap-door" Springfield era. I'll look into this just for grins. Bayberry is expensive the last time I saw it in a hobby/craft store.
 
Have you found a mold and sizer for the Miroku yet? Just curious... my original Springfield calipers out a touch over .58. You never know, I might get a wild hair to fire it someday, and need a slightly oversized minie ;-)
 
Evidently the ordinance department used bayberry wax for a time. At least they did during the "trap-door" Springfield era. I'll look into this just for grins. Bayberry is expensive the last time I saw it in a hobby/craft store.

Bayberry wax? Might have been a way to flavor your soup at the same time. :cool: I googled it and saw one source for $18.95/pound. I seem to recall paying about half that for beeswax.

Have you found a mold and sizer for the Miroku yet? Just curious... my original Springfield calipers out a touch over .58. You never know, I might get a wild hair to fire it someday, and need a slightly oversized minie ;-)

Not yet. I'm going to do a little shopping and try to pick up a used one before I commit. I'm thinking .581 or .582 - Peter, what do you suggest? If I go with a larger size I can always size it down later if needed without buying another mold.
 
Not yet. I'm going to do a little shopping and try to pick up a used one before I commit. I'm thinking .581 or .582 - Peter, what do you suggest? If I go with a larger size I can always size it down later if needed without buying another mold.

Saw you posted on the NSSA board. You'll get some replies fairly quickly. As for sizers, there are two different main types aside from those designed for the Lubrisizer. One is unthreaded for an arbor press and the other has 7/8x13 like a standard set of reloading press dies. I use the latter almost exclusively.
 
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