Compression in black powder cartridges?? PLEASE READ ALL ANTIQUE SHOOTERS

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FARMHANDYO

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Hi everyone,

Im making this post as a warning to all but also a question. I am new to reloading black powder cartridges and reload for a french model 1873 antique revolver made in 1875.

1. *WARNING*

Ive heard alot of talk from people on this forum about reloading black powder cartridges with smokeless powder. When I purchased my 1873 that's how I started. I heard from multiple members that as long as you use the right powder and keep it at a low charge that most antique firearms would be fine. So I reloaded 11mm french (a stubby 45 caliber french cartridge 190 grain bullet) with 3 grains of trailboss powder. The trailboss was not compressed and sat comfortably under the bullet. I was even told by a gunsmith that it would be fine and that the revolver was built like a tank. The first few outings were totally fine. The revolver was accurate reliable and the cases showed no sign of over pressure and I inspected the entire revolver when cleaning. One day I took out the revolver again with the same load. I fired 20 rounds with no issue then on the 21st round I heard a pop sound. I dont exactly know how to describe it but I knew that something was wrong. I took the cylinder out of the revolver and it was fine no bulging or anything. The revolvers barrel also showed no signs of bulging. But looking at where the hand comes out to rotate the cylinder I noticed in horror that there was now a 1 centimeter crack that went through both sides of the frame. I was pretty horrified by this and stopped shooting. I took the revolver completely apart and saw that none of the internals were damaged at all just that one crack. It was easy to get to and a gunsmith tig welded it for me. The revolver looks fine now you would never know that it had cracked. This is just a warning to people to be extremely careful or maybe to not load smokeless powder in this french revolver because it cannot handle it. I think that the sharp spike in pressure with smokeless is what cracked the frame of the revolver and the lack of hardening of the steel. This is just my experience and you can take it or leave it. Its your business after all but I felt like I had a responsibly to share this experience with other antique revolver owners.

2. Question:

I now shoot this revolver with 3fff black powder only GOEX. The revolver has now seen 200 rounds through it with black with no issues at all. The case can hold 11 grains without compression. My question is this. Is it okay to compress black powder in a cartridge? I can get 13 grains of 3fff in the cases and can hear the powder compressing when using a press seating the bullet. Is this okay to do? Is this common place since you want to have very little space in a black powder cartridge?
 
Some compression in a black powder cartridge is very normal and totally fine. Just like when you press the ball down on a cap and ball revolver you compress the charge somewhat. You don't want any air space in the cartridge.
 
I think the problem with your revolver frame and not the Trail Boss. Metal control in the 1800s was not always 100 % and perhaps you have a brittle frame. Relative to compressed charges, I don't think you gain anything with a compressed load in a handgun cartridge. In a rifle, light compression does give a more uniform burn rate but much less so for short shells and close ranges

cheers mooncoon
 
I have not done this, so take it for what it is worth. Had read to use a wooden dowel - as a "punch" to press down on the black powder to a mark that you made on that dowel - using the dowel to compress or to set the powder, not using the bullet to do so. Then seat the overpower wads / bullet as normal just onto the powder - that way the ball is not getting deformed...
 
Trail boss is actually a fast burning powder and spikes pressure quite quickly. Personally I use it in a few later antiques like the French 1892 but prefer slower powders like unique in the old iron guns.
And also stick with black in some.

A moderate amount of compression will give a cleaner combustion so I usually do a little in most uses. That said, a charge of only 10gr isn't going to compress much anyway.
 
vagrantviking said:
Trail boss is actually a fast burning powder and spikes pressure quite quickly. Personally I use it in a few later antiques like the French 1892 but prefer slower powders like unique in the old iron guns.
And also stick with black in some.

A moderate amount of compression will give a cleaner combustion so I usually do a little in most uses. That said, a charge of only 10gr isn't going to compress much anyway.
Click to expand...

That makes sense. I probably trusted the gunsmith a little too much telling me that it would be fine to do and that he does it all the time. My instinct was to only use black like I do for all my antique guns but unfortunately I took his advice instead of listening to my gut feeling.
 
Potashminer said:
I have not done this, so take it for what it is worth. Had read to use a wooden dowel - as a "punch" to press down on the black powder to a mark that you made on that dowel - using the dowel to compress or to set the powder, not using the bullet to do so. Then seat the overpower wads / bullet as normal just onto the powder - that way the ball is not getting deformed...
Click to expand...

if you load the shell with a drop tube and seat the slug with a tiny amount of compression, that should be adequate. If you over-compress the powder, if becomes a briquet and shoots slower; I speak from experience on that fact (in my rifles) I also think your gunsmith was correct to a point; the refining and composition of iron/steel in the 1800's was less than perfect and you may have had a pocket of brittle metal where the crack occurred and were just lucky it had not broken with a black powder load

cheers mooncoon
 
mooncoon said:
if you load the shell with a drop tube and seat the slug with a tiny amount of compression, that should be adequate. If you over-compress the powder, if becomes a briquet and shoots slower; I speak from experience on that fact (in my rifles) I also think your gunsmith was correct to a point; the refining and composition of iron/steel in the 1800's was less than perfect and you may have had a pocket of brittle metal where the crack occurred and were just lucky it had not broken with a black powder load

cheers mooncoon
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I think that it could happen to any 1873 french revolver. The place where it cracked is a extremely thin piece of iron. Maybe at most .3 of a millimeter thick. The sharp pressure curve of smokeless powder I am convinced is what cracked the spot.
 
I had a 1858 Remington C & B in 44 that I had a similar episode with. Black powder substitute made the old frame try to spit that barrel out...had a new Italian barrel and cylinder. Guessing the Italian job had metric threads...first cylinder of BP sub and the barrel jumped ahead two threads...yikes!
I pulled it back to a firing status with a good machine screw, applicable tap and solder. It'll still shoot...but the faith is gone.
Now and again I'm tempted to bob the barrel to about 2 1/2" and remove the charging assembly.
Got to love antiques though!
 
For my $0.02 cents worth I never shoot smokeless in an antique firearm, black powder only even in cartridge guns like my 1884 Springfield Trapdoor which shoots 45-70.

That said when loading for the Trapdoor to get the nominal 70g of ffG under a 500g bullet I use a compression die to compress the black powder by about 0.5". Same for my percussion revolvers especially if I am shooting conical bullets they do compress the powder a little more than the round balls.

Retreever
 
I wish I had a link or copy of an article I read years ago about the U.S. Navy experimenting with BP after a turret was blown off one of their ships. They used modern pressure testing equipment that wasn't available beforehand. One of their conclusions (and recommendations to the Ordinance dept.), was to stop compressing BP as it was discovered that severe pressure spikes to well over 120,000 PSI were possible ...3 times what they thought possible before. I cant remember charge size used but do remember that the general consensus of the article was that even small compressed charges can have pressures much in excess of what we previously thought.

This Navy report was in a gun mag or might even been in one of Sam Fadalias books... their recommendation was anything more than a very slight compression force from a slug base might not be a good idea.
 
fingers284 said:
They used modern pressure testing equipment that wasn't available beforehand. One of their conclusions (and recommendations to the Ordinance dept.), was to stop compressing BP as it was discovered that severe pressure spikes to well over 120,000 PSI were possible ...3 times what they thought possible before..
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that is completely opposite to my experience with rifle cartridges. For a brief time, I thought that compressed charges are like scotch whiskey --- if a little is good, a lot is better :>) The bullets shot several inches low at 100 yards. That is the same as what happens if you went to 1F powder from 3F. Heavy compression more or less makes the charge into a briquet. Powder burns from the surface in and if you compress too much you cram the powder granules together so tightly that in effect you have reduced the surface area. That may be different if you are talking about 10 or 20 lb charges but for much smaller charges like rifle shells, I don't think is true.

cheers mooncoon
 
Ever since I had that part of the frame tig welded its held up very well. I would also like to get a chronograph to see how fast the 190 grain bullets are traveling. I would guess that with 3fff compressed slightly that they are leaving the muzzle at around 700 fps. I wont ever sell the revolver just enjoy it. Its also so easy to take the entire thing apart to clean out the black powder residue.

https://www.youtube.com/watch?v=wkAcbyaQlpo&t=411s
 
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vagrantviking said:
Trail boss is actually a fast burning powder and spikes pressure quite quickly. Personally I use it in a few later antiques like the French 1892 but prefer slower powders like unique in the old iron guns.
And also stick with black in some.

A moderate amount of compression will give a cleaner combustion so I usually do a little in most uses. That said, a charge of only 10gr isn't going to compress much anyway.
Click to expand...

Huh! I was under the impression that Trailboss was a was the choice smokeless powder for antique revolvers. I switched from Unique a year ago for that reason. The number of squibs, amount of unburned powder, and inconsistent velocities with Unique were also contributing factors. Since switching to Trailboss all those issues have gone away. What am I missing?

Loading 38 Special for a 1893 Colt SAA (converted from 41LC by Colt in the 50's) and 450 Adams for a Webley MP.

Cheers
Moe
 
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mooncoon said:
Heavy compression more or less makes the charge into a briquet. Powder burns from the surface in and if you compress too much you cram the powder granules together so tightly that in effect you have reduced the surface area. That may be different if you are talking about 10 or 20 lb charges but for much smaller charges like rifle shells, I don't think is true.
cheers mooncoon
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The British experimented extensively with compressed BP charges partly to try to reduce the length of the initial straight cased Martini cartridge. To be effective there had to be a void running down the middle of the compressed powder charge to allow for complete and rapid ignition. There were no comments in the reports I read that suggested dangerous pressures encountered during their experiments.

milsurpo
 
Not all Black Powder is the same. Swiss doesn't need much compression, if any, but Goex does, in my experience. In my 45-70, the more I can cram in there, the more accurate it is.
 
Moe said:
Huh! I was under the impression that Trailboss was a replacement for black powder and was the choice smokeless powder for antique revolvers. I switched from Unique a year ago for that reason. The number of squibs, amount of unburned powder, and inconsistent velocities with Unique were also contributing factors. Since switching to Trailboss all those issues have gone away. What am I missing?

Loading for 38 Special for a 1893 Colt SAA (converted from 41LC by Colt in the 50's) and 450 Adams for a Webley MP.

Cheers
Moe
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The advantage of Trail Boss is that it's the lowest-density fluffiest smokeless powder, so the various issues of a tiny charge of denser powder being in the wrong part of the case for ignition or allowing multiple charges to inadvertently be loaded are reduced. If you're trying for the smallest possible smokeless charge it's what'll get you there. But it would still be faster-burning than black powder and so unrecommended for pre-smokeless antiques that should probably only be used with the black powder they were designed for.

Trail Boss is mostly for Cowboy Action or PPC where someone wants their revolver to barely go pop and minimize recoil, so usually single-action replicas or double-action guns.
 
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