Accuracy load for Black Powder

[BJung]

How do you improve the accuracy of your loads like a 50/70 or 45/70? Since the Black Powder quantity is fixed, do you mix it with a smokeless powder, fill the case with an inert filler, change the bullet weight or alloy? I am just curious just in case I buy a rolling block

 

[Jim Watson]

Since the Black Powder quantity is fixed,

What ever gave you that idea?
Adjustments in compression and OAL allow a lot of range in powder charge.

Duplex powder loading with a LITTLE smokeless UNDER the black is an advanced technique. I have not done it, not allowed by NRA. Don't mix.

I have never put non-gunpowder crap filler in a cartridge, just a hard card wad between powder and bullet.

Experimenting with bullets can get expensive, get some recommendations before you sink a lot of money into molds.
Not from me, I don't shoot those calibers.
20:1 lead-tin is a good standard alloy, SPG bullet lube.

 

[BJung]

Thanks for your reply. I only know about smokeless powder reloading. That makes sense that I can add or reduce black powder and then compress the bullet up to it or further to compress it. Is this how you determine the ideal charge or do BP cartridge shooters use a fixed charge and then adjust for the OAL only.

 

[Jim Watson]

I got my .38-55 load from a top shooter and was never able to beat it.

I have fooled more with .40-65, mostly varying OAL with different thickness overpowder wads. Bullet diameter was deceptive there, it shoots best with a .411" bullet in a nominal .408" Badger barrel. I assume the Browning's throat is that large.

Mike Venturino's 'Shooting the Buffalo Rifes' has good general and specific information.

 

[Ugly Sauce]

One inch at 100 yards. 80 grains of FFG Swiss, Speer 400 grain JSP. Black is just as accurate as smokeless.

Black powder likes to be compressed. So any charge where you get compression is good. It burns cleaner when compressed. With a cast 405 grain bullet and 70 grains of powder, IMHO, I think one will get just the right amount of compression. Best to compress the powder in a separate step, if you don't like deformed bullets. Some load 65 grains and compress with the bullet, to avoid the smashed bullet nose syndrome. !

I use pure soft lead.

 

[Ugly Sauce]

100 yards, replica LEE mold 405 grain cast bullet from soft lead. 72 grains Swiss black powder. Thin fiber card wad.

 

[BJung]

So what happens if you cannot find a good group after adjusting bullet seating depth. Would you change bullet weight or do you caculate a bullet weight based on what the gun was designed for or the barrel twist? Getting back to alloys, do you choose pure lead instead and adjust the alloy? I remember wads being mentioned. Are all BP cartriidges loaded with those, paperpatched, or powder coated?

 

[Roverguy]

The thing you have to understand is that unlike smokeless reloading, BP cartridge loading is more art than science, and not a little bit of magic.

First, everybody has very strong ideas about what’s the most important from compression to bullet alloy, bullet shape, to lube and more. And, generally speaking (albeit at least a little facetiously) if you don’t agree entirely with the dogma that person is preaching, you are lost.

There are, in fact, many, may variables. But generally speaking again, bullet fit and degree of obturation to seal the bore and limit gas cutting are very important. Bullet design is important to avoid nose deformation. Lube is pretty important. COAL is very important. Plus or minus 3 grs of powder is not very important as long as there is consistency. I would say that bullet fit and alloy are among the most important things. And if you don’t agree, you are damned ;-)

 

[dave951]

DO NOT go messing with duplex loads. Pressure curves are very different from real black and smokeless. Do some research on the Shiloh forum. Those guys shoot black powder cartridges all the time for accuracy at distance. You'll find the basics are- grade/brand of powder, bullet, powder compression, and wads. Bullets have a completely different set of variables from standard centerfire. Bullet shape, alloy, sizing, lube, and seating depth are all variables. If you're after accuracy, there's far, far more to this than just pouring some holy black in a case and stuffing a bullet on it.

I'm working with an original 1869 Rolling Block in 50-70. After playing with all the variables, this is the best target I could get. After close inspection of the throat area of the rifling, I found the rifling was worn to the point where it would only marginally stabilize a bullet. I sent the rifle off to Bobby Hoyt for a new liner and have only fired three shots since it got back. (Life and weather) I shot that group at 100yd and it looked like that small part of this one. I'm stoked to get this thing back to the range with the new liner.

 

[Czy_Horse]

Have you tried a powder drop tube? Using a drop tube, the powder is compressed as the brass fills. I use a 20" powder drop tube to compress charges of N130 in my 444Marlin.


Crappy picture but both piece's of brass contain equal weights of N130.
My numbers improved greatly using a powder drop tube, N130 powder, 265gr Hornady FP, 2322fps avg, ES 29fps, SD 10

 

[Jackrabbit1957]

I have 2 45/70s, a rolling block and a trapdoor. The roller likes a 350 to 405 grn bullet, the trapdoor likes a 250 grn pistol bullet. Trapdoor has a slower twist than the roller in the rifleing. I have not put either on on a paper target as of yet, just shot at targets 100 yards and out to 400 or so. The trapdoor is a lighter gun than the rolling block and with the same loads for the roller it beats me up pretty bad. Plus accuracy isn't there. It's happy....and so is my shoulder, with the pistol bullet. Been loading Pyrodex, 777, and the holy black, doesn't seem to care much.

 

[dave951]

Drop tubes are a must for black powder cartridge accuracy

 

[BJung]

Good to know but how will a drop tube help if the powder is compressed anyways?

 

[BJung]

DO NOT go messing with duplex loads. Pressure curves are very different from real black and smokeless. Do some research on the Shiloh forum. Those guys shoot black powder cartridges all the time for accuracy at distance. You'll find the basics are- grade/brand of powder, bullet, powder compression, and wads. Bullets have a completely different set of variables from standard centerfire. Bullet shape, alloy, sizing, lube, and seating depth are all variables. If you're after accuracy, there's far, far more to this than just pouring some holy black in a case and stuffing a bullet on it.

I'm working with an original 1869 Rolling Block in 50-70. After playing with all the variables, this is the best target I could get. After close inspection of the throat area of the rifling, I found the rifling was worn to the point where it would only marginally stabilize a bullet. I sent the rifle off to Bobby Hoyt for a new liner and have only fired three shots since it got back. (Life and weather) I shot that group at 100yd and it looked like that small part of this one. I'm stoked to get this thing back to the range with the new liner.
View attachment 1058813

View attachment 1058814

What is your opinion of FF powder vs Pyrodex?

 

[Roverguy]

Good to know but how will a drop tube help if the powder is compressed anyways?

The drop tube delivers compression. A compression stem and die can also do this. With properly soft bullets, compression by seating will cause bullet deformation and related problems.

 

[BJung]

The thing you have to understand is that unlike smokeless reloading, BP cartridge loading is more art than science, and not a little bit of magic.

First, everybody has very strong ideas about what’s the most important from compression to bullet alloy, bullet shape, to lube and more. And, generally speaking (albeit at least a little facetiously) if you don’t agree entirely with the dogma that person is preaching, you are lost.

There are, in fact, many, may variables. But generally speaking again, bullet fit and degree of obturation to seal the bore and limit gas cutting are very important. Bullet design is important to avoid nose deformation. Lube is pretty important. COAL is very important. Plus or minus 3 grs of powder is not very important as long as there is consistency. I would say that bullet fit and alloy are among the most important things. And if you don’t agree, you are damned ;-)

I assume bullet fit is like smokeless cast bullets that are .001" over the slugged bore. Traditionalists probably like lube but do others use powder coating? Would bullet casts consider bullet bhn as well by varying the tin mix and possibly adding lead with antinomy

 

[Roverguy]

What is your opinion of FF powder vs Pyrodex?

Next can of worms…

May I suggest a very good book? Paul Matthews “Loading Black Powder Cartridge Rifle”. Nobody will agree with absolutely everything in Mathews’ book, but it is a solid foundation and better than Internet question hour ;-)

https://www.trackofthewolf.com/Categories/PartDetail.aspx/273/1/BOOK-LBPRC

Also available on Amazon, EBay and elsewhere.

 

[Driftwood Johnson]

Mike Venturino's 'Shooting the Buffalo Rifes' has good general and specific information.

Howdy

I agree. MIke has one general chapter about how to load the big cartridges. Then he goes into the specifics of each of the old 'buffalo rifles' and the specifics of each cartridge.

As you can see, my copy is well worn.

Available on Amazon, I recommend it highly.

 

[ClemBert]

I use a drop tube to help fit 40gr 3fffg in a .45 Colt cartridge. Essentially, you are increasing your powder density similar to compressing. Still have to persuade a 250gr bullet to fit even with the drop tube.

 

[dave951]

Back on my desktop, lots here to unpack

Good to know but how will a drop tube help if the powder is compressed anyways?

Black powder will "settle" from vibration or a drop tube. Compression is mechanical crushing of the powder granules. In drop tubing, the grains generally settle about as far as they'll go and that last little bit of compression doesn't damage the granules nearly as much.

What is your opinion of FF powder vs Pyrodex?

Just say NO to Pyrodex for this use, for any gun you care about. Pressure curves are far different that black powder, fouling is abrasive and harder, and it's far more corrosive than any black ever thought of being. Every gun I've seen ruined was shot with "only Pyrodex" cleaned, oiled and then stored. To really get all the corrosiveness out you have to clean multiple times. With real black powder, you need only clean once, dry and oil. I use Windex in my competition muskets and have no issues. The water in Windex cuts the fouling, the ammonia is a base that neutralizes the acidic residue, and the alcohol aids in drying. I can clean my competition musket in 5 minutes and it still shoots 2moa. The best use I've found for Pyrodex is killing moles in my lawn. Pour some in their little holes, add fuse, a match and fun times.

I assume bullet fit is like smokeless cast bullets that are .001" over the slugged bore. Traditionalists probably like lube but do others use powder coating? Would bullet casts consider bullet bhn as well by varying the tin mix and possibly adding lead with antinomy

Bullet fit is a variable. It depends on rifling type, depth, lead alloy, etc, BUT there are a few generalities. First, pure or nearly pure lead and by nearly pure, no antimony, maybe 2-4% tin. Alloy is important as black powder causes obturation on firing. If the bullet alloy is too hard, the bullet will not upset to perfectly fit the bore. Size depends on rifling and bore, in general though .001-2 over bore size. Weight is very important. Lube is absolutely necessary to keep fouling soft and under control. Powder coating will not substitute for lube on black powder rounds no matter what you're read on smokeless forums, it simply won't help. And before you even think it, yes, I tried it, with and without lube.

From the comments you've made, you need to forget what you know about smokeless reloading. Most of it simply doesn't apply. Start from scratch. Hang out on the Shiloh and BPCR forums to learn how those guys are making 1k yd shots with black powder cartridge rifles and I'll give you one hint, it ain't with Pyrodex nor powder coating. Those in the running for the top 10% are having velocity deviation on the order of 5 (or less) feet per second from shot to shot, verified by chronograph. I think they may be on to something.

 

[tark]

Drop tubes are a must for black powder cartridge accuracy

I have found something better than any drop tube. Charge the case and set it on a plate that vibrates. Watch as the powder settles into the case. It will be settled deeper into the case than with a drop tube. Better yet, use both. I have little trouble getting a full 70 grains of 2F into a W-W case with a 500 gr. bullet seated over it, without undue compression.