Minie ball keyholeing

[sandy4570]

What cause the Minie ball to keyholeing at 50 yards? I shoot Armi Sport 3 band Enfield P53 using 50 grains of Pyrodex RS and Goex 2F .I replace the nipple so I can use #11 cap and no hang fire occurred. The Minie ball is Lyman thick skirt .577 and 611 grains(according to the seller/caster). The Minie works fine with other rifles I have. The Enfield was second hand and supposedly former owner use it for reenactment. The rifle is in very good shape except bayonet mark and scratch near muzzle. The bore is mirror bright with good rifling. The only unusual thing I noticed was that the Minie drop all the way down with no effort at all.
1. Is this the case of undersized Minie/over size bore? But isn't .577 is standard size Minie ball?
2. Should I try leave the paper on the bullet(Paper cartridge I mean) and ram it down like what the British military used back in the day. The Minie has 2 grease grooves and I smear the grooves with Bore butter.
3. Will it help bumping charge up to 60 grains?
4.Would it help if I use thin skirt Minie?

 

[Jim K]

A minie ball tumbles for the same reason any other bullet from a rifled barrel does so, it is not being stabilized by the rifling. So you have either a too-light charge (I recommend 60-65 grains) or a too small bullet, or both. Try the increased charge first, and let us know what happens.

Jim

 

[PRD1]

Several things to try:

There is no workable standard size for modern minie rifles - the original standard bore diameter for the Enfield was .577", while the British standard diameter for the ungrooved bullet was .550 - there was some variation in both.
The U.S. standard rifle-musket bore was .580", and the minie was supposed to be of a diameter to permit easy loading when the bore was clean.

Modern reproductions of both types vary considerably in actual bore diameter, and serious shooters measure the bore diameter and size their minies as close to that dimension as will permit loading in a clean bore.

Your heavy, thick-skirted minie probably needs a heavier charge to obturate, and BP works better (IMO) than Pyrodex. The standard charge for the British loading was 2 1/2 drams (about 68 1/2 grains) of fine-grained powder (like 3Fg - per Hans Busk 'Handbook for Hythe', 1860). The typical U.S. charge was 60 grains of 'musket powder'.

You can try leaving the paper on the bullet, if it can be loaded that way, though the paper in the British cartridge was waxed, and the uncannelured bullet was not lubricated.

Increasing the charge is a good thing to try.

If you want to use a lighter-than standard load, a thin-skirted bullet is a better choice.

Good Luck!

PRD1 - mhb - Mike

 

[Jim K]

Later in the war, the U.S. was using so many Enfields that most of the issued ammunition was made with .577 bullets and the cases were so marked. It worked OK with both the Enfield and Springfield rifles.

Jim

 

[vagunmonkey]

Could also be the minie's are made of hard lead.

 

[sharps59]

#1 is the correct answer if as you said it shot well in other muskets provided the lead is the same. Ive used that bullet w 48 grn 3ff w good results.
One other thing muskets that were used by reenactors normally have the breach area eroded away. shooting blanks is the worst thing you can do to a musket. so you may have a breach problem.
Also I would go back to the musket nipple.

 

[Curator]

My Armi Sport P53 likes .580 diameter minie bullets. I lapped out the Lee .578 "oversize" "Modern-minnie" mold to get a good slide fit and accuracy improved. Another factor with minie key-holes is the possibility your bullets have a void at the top of the hollow base--that creates an unbalanced situation. I add about 1/2% tin to the pure lead and cast hot to prevent this.

The original Enfield cartridge had a shallow hollow-based bullet of .550 diameter but was loaded with two wraps of paper and dipped in bee's wax. It also had a tapered wood plug in the base of the bullet to facilitate the expansion of the base into the rifling. To get the thick base Lyman slugs to shoot, you might try a powder charge of 70 grains of FFg and load about a half measure of cream of wheat or grits over the charge. The cereal filler will pack up into the base upon firing and seal off the powder gas. Accuracy will improve and you will get less fouling in the bore.

 

[sandy4570]

Thanks everyone for the great advice. Much appreciate all the great input so I don't have to start in the dark . I will try as follow
1. Increase the charge incrementally to 70 grains and see how it goes
2. Try what Curator's method using cream of wheat as a base plug ( I assume Corn meal can be substitute for cream of wheat or grit )
3. Switch to Musket cap and try again
4. Try thin skirt Minie ball
5. Try .578 diameter Minie ball
6. Get 3F and try but this have to wait until my next black powder order

I will report the result after the range visit

 

[4v50 Gary]

How's the crown?

 

[sandy4570]

The crown is fine .

I just get back from the range and here is what happened
try #1 and at 60 grains of Goex 2F,no more keyhole but the rifle hit high to the right. I used Kentucky Windage and got two shots touching at the lower right corner of the 5.5 Inches bright orange bulleye. Subsequent shots landed all over the paper. I cleaned the bore with Balistol and it did not help.

I tried .585 Minie ball ( ordered by mistake, it was made for Snider ) it was tight fit and I feared the skirt probably not going to expand and grip the rifling with such tight fit ball. I fired about eight of this Minie. No keyholeing but it hit low with windage spotted on but I could not get it to hit target .

For the heck of it I tried patch round ball using the same load as my Zouave - 75 grains of Pyrodex RS,0.15 patch and .575 lead ball and the gun hit dead center with six o'clock hold aim about two inches low. I was able to get four more shots into the bulleye. The gun clearly like patch round balls.

I will try #2 and 4 next time and see of the accuracy will improve.

 

[BHP FAN]

I like the round ball myself, it's more accurate and easier to load in my underhammer sniper rifle.

 

[4v50 Gary]

Sandy, that's interesting that yours shoot a patched round ball really well. My 24" Parker Hale threw the balls all over the place. It shot fine with minies.

 

[72coupe]

R. Lee Ermey had a tv show on the History channel a few years back. They shot quite a few rifles with minnie balls and it seemed that nearly all of the key holed. I wondered if they knew what they were doing.

 

[BHP FAN]

Prolly too thick of skirts, and too ''soft'' a load.

 

[4v50 Gary]

Thick skirts won't expand enough (or the lead has too much tin or another alloy that make it too hard thereby making expansion of the skirt iffy). Too thin and it can blow out.

 

[EljaySL]

It definitely is a process to get minie balls to work well. Just as an example in my Zouave reproduction, it shoots a decent group with .578s but .575s have trouble hitting the paper at 20 yards. And there's some relatively narrow range of loads where it works even then. It's not like roundball where you can tune to your hearts content without worrying about basics like is your rifling really contacting the lead... so it's a great plinking gun and packs a punch but I don't know that I'd try any precision work with it.

 

[MEHavey]

Sandy, go with the Lyman thin skirt #575213-OS (Old Style)
http://www.trackofthewolf.com/Categories/PartDetail.aspx/1200/1/LYMAN-575-213-OS
Ensure you have Pure Lead

That's the one [us] N-SSA'rs standardize on for darn near everything.... in my case a Parker-Hale Enfield Musketoon, a Zouve, and my competition (original) `61/63 Colt's Special Model Springfield.

And use the standard service load of 60gr 2Fg/GoEX
3:1 Crisco/Beeswax for lube.

 

[Mike OTDP]

45-50 grains is OK with 3F powder. From the description, the bullet is undersized. The gouge number in the N-SSA is to go .001 under bore diameter for a minie.