Choice of the right minie bullet

[Cannonman1]

I have a minie mold by Lyman.. 577-611. This round is a thick skirted bullet that comes out of the mold at .575. What powder charge FFFg would you use to expand that skirt? I expect 55 grains should do it but want to hear if anyone out there has experience with this particular bullet. I will be shooting them out of several Parker Hales's with progressive depth rifling if that makes a difference.


Thanks
Bill

[Michael Bodner]

Bill,

The shortest answer to your question is: Around the 40-44 grains of 3Ffg will be a good starting point for a usable load.

With that said, we need to discuss several issues. You state that the bullet casts out at about .575. What is the size of your bore? If you have a .580 then a .575 bullet will never expand enough to grab the rifling (regardless of what charge). In general, you want you bullet to be between .001 and .002 smaller than the bore. Then you should be about to get sufficient expansion of the skirt to grab the rifling in the 40-45 gr range. Once you know that you are (the bullets don't tumble and keyhole) then you can start varying the charge by 1/2 grain (up or down) to see what gives you the tightest grouping.

The tricky part is measuring your bore. Because of the odd number of lands and grooves, you can't simply stick a caliper into the barrel. Ideally, you install a plug gauge (a simply round rod ground to exacting standards) and keep trying sizes until you find the last one that fits.

See if you can find a local machine shop that will measure your bore inner diameter using plug gauges. Tell them that you are in the 0.575 to 0.585" range and ask if they can help. Some will ask for a few $$ and other will find the task cool enough to say 'No charge'.

Once you know the correct bore, find a bullet that is about 0.001 " smaller and start using it.

I'm sure some others will also chime in, but that's a good place to start.

Good luck!!

-Mike

[John Bly]

That 577611 bullet was used by some to shoot the 200 yd musket match at Friendship. I don't know what powder charge they used. With that thick skirt I would expect your charge of 55 grains or 60 might work OK. Bootsie is right on the size of your bullets to the bore, too small and you won't get the accuracy you need. I tried that 577611 bullet some years ago and never got it to shoot well enough. I made a new base plug to get a thinner skirt and that didn't shoot well either. You might want to try some of the 575213 bullets.

[Kevin Tinny]

Thanks, everyone:

Some are aware that shooting musket matches at Friendship can, depending upon the NMLRA RULES and the shooter's preferences, be quite different than at N-SSA skirmishes.

Friendship musket shooters, the last I read the Rules, are allowed 45 minutes to fire unlimited sighters and five record shots in a relay of their choice. They can WIPE BETWEEN SHOTS and sit-out unfavorable conditions.

In the late '70's and into the 1980's the NMLRA sold a book entitled:
MUZZLE LOADING SHOOTING AND WINNING WITH THE CHAMPIONS.

in this book, Peter Allan, a musket match and aggregate winner and record setter, shared ALL of his knowledge and equipment information involving "what's, why's and how's".

Pete is a humble, self-taught whiz-kid with anything mechanical. He thinks outside the box. He camped next to me for many years and was a fine person.

Anyway, he rifled his own barrels and designed and made his own "minie-style" bullet. His raw barrels were approximately six inches longer than finished length. He used the cut off section to make a tapered, straight line sizing and rifling ENGRAVING die. His minie was SOLID AND SQUARE BASED WITH NO CAVITY AND HAD A SINGLE LARGE LUBE GROOVE.

The pre-rifled, naked bullet was very tight fitting and, because of the absence of fouling, it could be more consistently seated on the powder without bouncing a heavy ramrod. His chronographed loads had an exceptionally narrow extreme muzzle velocity spread, which is critical for minimizing vertical dispersion at our slower velocities.

So, MOA was the result in his NBPRP Distinguished classified hands until an arm injury sidelined him.

Yes, his setup is way different than N-SSA allows, but it shows what a musket can achieve.

Respectfully,

Kevin Tinny
42nd NY

[ms3635v]

Canon Man,

When I started skirmishing in 1979 I shot a Parker Hale P58. The Lyman old style .575213OS was the bullet I used with 45 grains of 3F (DuPont when I started, then GOEX). This combination worked very well and I never had any problems with accuracy at 50 and 100 yards,

[Cannonman1]

Bill,

The shortest answer to your question is: Around the 40-44 grains of 3Ffg will be a good starting point for a usable load.

With that said, we need to discuss several issues. You state that the bullet casts out at about .575. What is the size of your bore? If you have a .580 then a .575 bullet will never expand enough to grab the rifling (regardless of what charge). In general, you want you bullet to be between .001 and .002 smaller than the bore. Then you should be about to get sufficient expansion of the skirt to grab the rifling in the 40-45 gr range. Once you know that you are (the bullets don't tumble and keyhole) then you can start varying the charge by 1/2 grain (up or down) to see what gives you the tightest grouping.

The tricky part is measuring your bore. Because of the odd number of lands and grooves, you can't simply stick a caliper into the barrel. Ideally, you install a plug gauge (a simply round rod ground to exacting standards) and keep trying sizes until you find the last one that fits.

See if you can find a local machine shop that will measure your bore inner diameter using plug gauges. Tell them that you are in the 0.575 to 0.585" range and ask if they can help. Some will ask for a few $$ and other will find the task cool enough to say 'No charge'.

Once you know the correct bore, find a bullet that is about 0.001 " smaller and start using it.

I'm sure some others will also chime in, but that's a good place to start.

Good luck!!

-Mike

I took one of the minie's (measured at .575) and a slim (1/4 inch) strip of paper.. Paper came out at .003 thickness.. and I placed it alongside the bullet (on one side only) with the end of the paper bent underneath it, into the bore.. fit like a glove. I think I can safely assume the bore is .003 bigger than the bullet. That would be outside of your .001 - .002 range but close. I am going to try it and see.. Progressive depth rifling may make the difference here but if not I will get a little larger mold. Any suggestions on a source for one that casts .577
Comment, if you would, on what you think of my solution to obtaining a bore size using paper.. I thought that was a good way to do it.

Best Regards
Bill

[ms3635v]

Moose Moulds makes an Old Style Minie in .578" and that would size nicely to fit your needs. There are several people making excellent sizing dies depending on what type of set-up you are looking for, i.e. push-through, lubrisizer, or a 7/8 x 14 die that will fit in most reloading presses.

[Michael Bodner]

Bill,

Using the paper was very clever indeed!!! At least you have a pretty good idea where you are. By all means, give it a go and see what happens. Don't go out past 50-yards until you know you can hit paper.

Use a LARGE and NEW piece of cardboard (or place a clean, unshot sheet of paper over it so you can easily find your holes no matter where they land. Be aware that at 50 yds, an unmodified set of sights will hit HIGH even at the lowest sight setting (typically).

If you get any keyholes (sideways landing of the bullet) you'll be able to know that the skirt is NOT grabbing the rifleing enough (or at all). Go UP in powder charge and see if it stops. If it doesn't, then either your lead is too hard or the bullet is too small.

Good luck and let us know how it works out, McGiever!!

-Mike

[jonk]

That was the first bullet I ever shot, before I even cast my own. I was using 2f at the time, and found that best accuracy was with 70 gr. Later I tried 3f and got it to do well with 58 gr. So your guess of 55 might be a good starting place.

Then I got a 575213 mold and stopped buying them pre-cast, and since, a lot more molds.

[Chris Sweeney]

the problem with checking your bore diameter at the muzzle is that you are only checking it at the muzzle. It is not unheard of for there to be a pinch point deeper in, and/or the muzzle can be worn a thou' or more by ramrods or cleaning rods. The best way to check is with a gauge pin.