Airspace In Black Powder Cartridge Rifle

Status
Not open for further replies.
krinko

krinko

Member
Joined
Aug 15, 2010
Messages
308
Location
Omaha-ha-ha
OK, so it's supposed to be dangerous to leave an air space at the top of the powder column in a BP cartridge. I'm not sure why or how it happens---maybe it's like dust in a grain elevator---but anyway there's a possibility of an explosion. OK.
So this gets me thinking about the paper cartridge Sharps '63. Hmmmmmmmmmmmmmm.
The breechblock of this rifle has a tremendous open area around the tube that funnels the cap fire down and into the main charge.
Whether you cut off the back of the paper closing the block, or use the method that relies on thin paper and does not cut off the back of the cartridge; there is going to be a large air space at the bottom of the powder column every time you fire the rifle.
Yet nobody squawks, nobody runs around with their hair afire.
I am confused.
Does the location of the air pocket in the powder column matter that much?
-----krinko

PS Did they make good Sharps carbines in Farmingdale N.Y.?
Because I got one today.
 
While it is never suggested that airspace/loose powder is a good thing, the "YourGunWillBlowUp" argument loses a bit of steam in the face of the fact that Sharps rifles using CutTheTailOff cartridges have been in use since 1850 without such a mishap. (Loyal PeanutGallery fans correct me if I'm in error).

HOWEVER, I've found ignition in the CutTheTailOff cartridges to be significantly less reliable, and have always suggested shooters at the range make/use flat-base cartridges, which have performed instantaneously/without fail.

(Skirmish data from back when I was a real person)
 
i dont know about the paper cartridges but dont leave a air space in brass cartridges with black powder. many a chambers have been ringed that way. years and years ago on a 34 inch barrel i go distracted putting a bullet into a muzzleloader barrel i ringed the barrel. it was made of modern steel and a nice ring was put in it. i cut it of just below the ring. the barrel was still very accurate. i then had a carbine with a 26 inch barrel. that gun is still shooting wild hogs. never ever leave a airspace in front of black powder. one barrel making co. uses leaded steel for those that are not carefull with their muzzleloaders. leaded steel will not blow apart but really make a big bulge. of course the gun is ruined but you still have your hand.
 
This is pure speculation, I cannot prove it and have no desire to try to prove it! But it seems to me that as long as the initial ignition happens with the powder between the ignition and projectile, then the pressure will build up in line with the open bore and the projectile will accelerate down the bore as it should.

If there is a big enough air space inside the cartridge to allow ignition to flash over the top surface of the powder, then the powder will burn sideways inside the case or chamber which changes the direction of the pressure impulse away from inline with the bore.

So, a very small gap would still allow ignition and pressure to proceed from rear to front. A large air gap allows burning and a pressure spike in a different direction.

Pure guessing on my part. Whatever the truth is, I will continue to eliminate air space.
 
Someone asked a similar question on Castboolits and below are a couple of the answers.

My own answer would be if it's only 60 grains of powder and the gun has a breechblock that was designed to withstand the pressure including having an air space, then loading with an air space is a safe procedure that shouldn't result in any damage.
Either the steel is designed to withstand the pressure without being ringed,or the excess gas is bled away to prevent damage or both.

In a muzzle loader, an air space isn't considered acceptable because it can ring the barrel (which is to cause it to bulge).

When one considers that there can be air space when loading with pellets, then there must be considered to be an acceptable amount of air space vs. an unacceptable amount of air space.
The amount of acceptable air space may be in proportion to the strength and thickness of the steel in relation to the amount of the powder charge being loaded.
A small charge with a little air space may be safer than a large charge with a lot of air space.
Since there's a risk of damage, it's better to follow the general rule of no air space than to be lax and allow too much air space.
This may illustrate that there's exceptions to every rule, but that doesn't mean that the rule isn't useful and shouldn't be followed since it's there for a reason.

And simply discussing the safety of having an air space with different types of ammo. doesn't address how it can affect accuracy and performance if at all.
Just because having an air space can be safe in a Sharps doesn't mean that it doesn't affect consistent accuracy or velocity.

=============
#1

"In general, airspace is not desirable in BP loading, but the damage caused by it mostly applies to BP cartridge arms, where a chamber ring can interfere with extraction - we're not talking blowups here (except maybe when it comes from a stuck bullet with another round fired behind it). The Sharps percussers were intended to be loaded this way, and at most you'd get some scoring in the bushing, which should pose no real problems. The "air gap", in any case, is distributed here along the length of the cartridge, and not just behind the bullet.

Moreover, the practise of breech-seating the bullet in a BP cartridge arm, and then inserting a case of powder topped off with wads, also often leads to a 1/8" to 1/4" gap, and - although I have asked around the BPCR community - no-one has reported any problems from this technique (where any damage would be beyond the chamber, in the leade, and shouldn't affect chambering or extraction). I've never made up paper cartrides with the "ring-tail" bullet, but have shot an original New Model 1863 Sharps carbine quite a bit in past years (also a Starr) with loose powder and certainly some gap, with no problems. But, DO keep the gas check clean and well lubed, and clean out the flash passage thoroughly after shooting. "
=============
#2

"The percussion Sharps is designed so that it is impossible not to have air space as ther is a cavity in the breach block that only gets powder in it after the cartridge explodes (unless you load it from the muzzle which was a selling feature to the army in 1852)."

http://castboolits.gunloads.com/showthread.php?30134-54-cal-IAB-sharps
 
Last edited:
krinko said:
OK, so it's supposed to be dangerous to leave an air space at the top of the powder column in a BP cartridge. I'm not sure why or how it happens. .
Click to expand...

To clarify, it is dangerous to leave an air gap between the projectile and the powder column in a muzzle loader. This happens when the loader fails to seat the projectile against the column of powder. IF it was a very small gap, possibly not a problem, but too much and it acts as a barrel obstruction. The same idea was passed on when cartridges for black powder were developed, especially since a lot of the cartridges were (or are) loaded with much finer granulation of black powder than their muzzleloading ancestors. Faster deflagration rate = faster pressure spike.

The idea was/is that when a person was downloading the powder load, perhaps for target shooting, the gap could be large enough to cause a problem. Imagine the .45-90 Sharps cartridge loaded with only half the powder, and imagine that powder being 4Fg.....

The reason why the back end of the breech in a Sharps doesn't cause a problem is the same reason none of the caplock muzzleloaders have a problem..., the area begins the deflagration of the powder column, so it's already partially pressurized with the explosion of the cap, but if there is an air gap ahead of the main powder column, there is much more volume there, so the potential pressure spike is much much higher. One can, in some cases, have enough back pressure in a muzzleloader that the hammer striking the cap is forced backwards by escaping gas, back to the half-cocked position when the main charge deflagrates. This is also why there is no problem with the rear of the column having a space..., there is no real "obstruction" there. There is a thin metal cap, and the face of the hammer over the tip of the nipple, and this is quite less of a pressure problem than a 400 grain projectile sitting atop the powder column with an air gap. ;)

It's probably not an issue with a Sharps, with the massively robust action to hold in the pressure. I, for one, don't see a need to test that conjecture...as it can't be "good" for a Sharps' chamber, or any muzzleloading rifle barrel.

LD
 
"The percussion Sharps is designed so that it is impossible not to have air space as the is a cavity in the breach block that only gets powder in it after the cartridge explodes"
Click to expand...
That is absolutely incorrect. Cut the tail off "tailed" Sharps cartridges and you immediately spill loose powder into the breechblock cavity (which quite large)*, ...and ...actually produces that very slanted ignition surface mentioned as "dangerous" in previous posts.
* http://www.ssfirearms.com/prodimages/large/w17056-1.jpg

While still not recommended, I would appreciate some citation of actual chamber ringing evidence from BP airspace.
(i'm always open to new info)
;):what:
 
MEHavey said:
That is absolutely incorrect. Cut the tail off "tailed" Sharps cartridges and you immediately spill loose powder into the breechblock cavity (which quite large)*, ...and ...actually produces that very slanted ignition surface mentioned as "dangerous" in previous posts.
* http://www.ssfirearms.com/prodimages/large/w17056-1.jpg

While still not recommended, I would appreciate some citation of actual chamber ringing evidence from BP airspace.
(i'm always open to new info)
;):what:
Click to expand...

1. I provided the URL for the Castboolts thread where I copied and pasted those 2 statements from posts about there being chamber air space.

In addition,. here's another statement from the same thread that was posted by our own THR member named "curator" who also clearly states that an air space exists after he loads his Sharps with 60 grains of powder.

Post #16
"....My best load is using a .570 round ball and about 60 grains of FFg black powder. This does leave an air space in the chamber but it seems to shoot OK....."

http://castboolits.gunloads.com/showthread.php?30134-54-cal-IAB-sharps

2. As far as my statement about ringing a barrel by leaving an air space between the powder charge and projectile, I was referring to muzzle loaders.
I said,
"In a muzzle loader, an air space isn't considered acceptable because it can ring the barrel (which is to cause it to bulge)."

Regarding Sharps I also stated,
"Either the steel is designed to withstand the pressure without being ringed, or the excess gas is bled away to prevent damage or both."

I never said that a Sharps chamber has actually ever been ringed.

You seem to be asking about a ringed chamber, when I was mostly describing how a barrel can become ringed.
I don't know of any Sharps ringed chamber which was the point of my post and reference posts.
I was simply trying to explain why Sharps chambers don't get ringed as far as I know.
Because they are designed and made to be strong enough not to be damaged by the air space.
It seems that you may want citation evidence about chamber ringing which I don't know about unless a defective Sharps was ever made.
I don't want to look for a needle in a haystack, don't intend to or claim that there ever was one.
It's simply a theoretical discussion about why to my knowlwedge, a hypothetical possibility doesn't occur which others seemed to verify that it doesn't occur despite there being an air space present.
 
Last edited:
arcticap said:
Someone asked a similar question on Castboolits and below are a couple of the answers.

My own answer would be if it's only 60 grains of powder and the gun has a breechblock that was designed to withstand the pressure including having an air space, then loading with an air space is a safe procedure that shouldn't result in any damage.
Either the steel is designed to withstand the pressure without being ringed,or the excess gas is bled away to prevent damage or both.

In a muzzle loader, an air space isn't considered acceptable because it can ring the barrel (which is to cause it to bulge).

When one considers that there can be air space when loading with pellets, then there must be considered to be an acceptable amount of air space vs. an unacceptable amount of air space.
The amount of acceptable air space may be in proportion to the strength and thickness of the steel in relation to the amount of the powder charge being loaded.
A small charge with a little air space may be safer than a large charge with a lot of air space.
Since there's a risk of damage, it's better to follow the general rule of no air space than to be lax and allow too much air space.
This may illustrate that there's exceptions to every rule, but that doesn't mean that the rule isn't useful and shouldn't be followed since it's there for a reason.

And simply discussing the safety of having an air space with different types of ammo. doesn't address how it can affect accuracy and performance if at all.
Just because having an air space can be safe in a Sharps doesn't mean that it doesn't affect consistent accuracy or velocity.

=============
#1

"In general, airspace is not desirable in BP loading, but the damage caused by it mostly applies to BP cartridge arms, where a chamber ring can interfere with extraction - we're not talking blowups here (except maybe when it comes from a stuck bullet with another round fired behind it). The Sharps percussers were intended to be loaded this way, and at most you'd get some scoring in the bushing, which should pose no real problems. The "air gap", in any case, is distributed here along the length of the cartridge, and not just behind the bullet.

Moreover, the practise of breech-seating the bullet in a BP cartridge arm, and then inserting a case of powder topped off with wads, also often leads to a 1/8" to 1/4" gap, and - although I have asked around the BPCR community - no-one has reported any problems from this technique (where any damage would be beyond the chamber, in the leade, and shouldn't affect chambering or extraction). I've never made up paper cartrides with the "ring-tail" bullet, but have shot an original New Model 1863 Sharps carbine quite a bit in past years (also a Starr) with loose powder and certainly some gap, with no problems. But, DO keep the gas check clean and well lubed, and clean out the flash passage thoroughly after shooting. "
=============
#2

"The percussion Sharps is designed so that it is impossible not to have air space as ther is a cavity in the breach block that only gets powder in it after the cartridge explodes (unless you load it from the muzzle which was a selling feature to the army in 1852)."

http://castboolits.gunloads.com/showthread.php?30134-54-cal-IAB-sharps
Click to expand...
Think in the case of shot even though there is air space between the shot it has no effect as long as the shot is pressed against itself uniformly.
 
Guys, I'm not buying it.
Please cite an example (not explanatory theory) of a ringed/bulged barrel from a known BP airspace problem.

As noted before, I'm open to learning.
 
...and . . . (in answer to a prior question)...

Of my several Sharps, two of them (a `59 and a `74) are Wolgang Farmingdales from the very early 80s.
Both are absolute jewels.
 
MEHavey said:
Guys, I'm not buying it.
Please cite an example (not explanatory theory) of a ringed/bulged barrel from a known BP airspace problem.

As noted before, I'm open to learning.
Click to expand...

There's a first hand experience described in post #48 of this thread. --->>> https://www.muzzleloadingforum.com/threads/short-started-ringed-bulged-barrels.70006/#post-866049
The entire thread seems to be the result of another person posting who also had a bulged barrel and a call to a barrel maker was made about its safety in post #1.
 
If I read that post (and the preceding/following posts in the thread), I can't find evidence of when/how the bulge mentioned in the pawn-shop CVA occurred... only that the buyer found one after he bought it. (BTW: most all the discussion of barrel anomalies appear to surround conditions wherein the most of the entire barrel are left as airspace)

Does anyone have personal experience (or witness) to such a bulge happening with BP at anything short of literal feet of airspace ahead of exceptionally-high charge weights?
 
MEHavey said:
If I read that post (and the preceding/following posts in the thread), I can't find evidence of when/how the bulge mentioned in the pawn-shop CVA occurred... only that the buyer found one after he bought it. (BTW: most all the discussion of barrel anomalies appear to surround conditions wherein the most of the entire barrel are left as airspace)

Does anyone have personal experience (or witness) to such a bulge happening with BP at anything short of literal feet of airspace ahead of exceptionally-high charge weights?
Click to expand...

Did you read post #48 on page 3 about how the Thompson Center .45 barrel was ringed due to being short started and not rammed home?
It's a crystal clear eyewitness account. --->>> https://www.muzzleloadingforum.com/...inged-bulged-barrels.70006/page-3#post-876601
======

"I agree whole heartedly with this...and I speak from experience. A few years ago, I bought a used .45 t/C Hawken. I ALWAYS run a tight oiled patch down the bore of any muzzleloader I buy used, and this one proved to be fine. My very first range session with this rifle and I was getting 2" groups at 50 yards with the first roundball load I tried. A friend of mine was with me that day and we were talking about how well the rifle was shooting...and before you know it, I short started a ball and shot it without ramming it home.
I really didnt figure it hurt it, so I continued shooting. My 2" groups dissapeared and became shotgun patterns. I checked the bore and sure enough, I had ringed the barrel. The load was only 70 gr. of 3F Goex.
Now Im not saying this will happen to all rifles that get ringed/bulged...but I know for fact that I ruined a damn fine shooting rifle that day for sure. There were no outwards signs of a bulge either, but inspection with a borelight made the ring obvious."
 
Last edited:
arcticap said:
Did you read post #48 on page 3 about the how the Thompson Center .45 barrel was ringed either by being short started or the ball not rammed home?
It's a crystal clear eyewitness account. --->>> https://www.muzzleloadingforum.com/...inged-bulged-barrels.70006/page-3#post-876601
======

"I agree whole heartedly with this...and I speak from experience. A few years ago, I bought a used .45 t/C Hawken. I ALWAYS run a tight oiled patch down the bore of any muzzleloader I buy used, and this one proved to be fine. My very first range session with this rifle and I was getting 2" groups at 50 yards with the first roundball load I tried. A friend of mine was with me that day and we were talking about how well the rifle was shooting...and before you know it, I short started a ball and shot it without ramming it home.
I really didnt figure it hurt it, so I continued shooting. My 2" groups dissapeared and became shotgun patterns. I checked the bore and sure enough, I had ringed the barrel. The load was only 70 gr. of 3F Goex.
Now Im not saying this will happen to all rifles that get ringed/bulged...but I know for fact that I ruined a damn fine shooting rifle that day for sure. There were no outwards signs of a bulge either, but inspection with a borelight made the ring obvious."
Click to expand...
I've gotten A few used rifles and thankfully never short started any round, was taught many yrs ago when I had a single shot pistol kit, warning was very clear and I have taken it to heart. Good news is you can usually find used or like new barrels on Ebay, I've got assorted caliber and twist barrels for my Thimpson and Investarms sidelocks, which are interchangeable as long as the barrel diameters are the same.
 
i have to know:is mehavey saying you cant ring a barrel or chamber in a black powder rifle? is that is what he is saying? as to the sharps being a strong action, the wincester high wall is way stronger and strongest yet is the new remakes of the stevens 44 and 1/2. again, does he say you cant ring their chambers or barrels. or even a front stuffer barrel. i dont want to assume anything just the essence of what he said.
 
BP Cartridge rifle is the topic.
There we're talking fractions of an inch to a inch max (hence the related discussion of the percussion Sharps chamber air space in tailed-cartridge cutoff)

If you leave a 2-foot dead space ahead of a 100gr slug of accelerating BP, we're in a different ball game.





(BTW, if you tip the rifle down to get the powder up against the ball, then ignite the tail end of the powder train/burning forward with that powder column held against the ball by building pressure ... different ball game again.)
 
Last edited:
sorry, i should not respond to this. it takes a lot less than 2 ft to ring or blow out a barrel with black powder. respond as you want but their will be no more from me.
 
MEHavey,
Appreciated you mentioning your Farmingdale Sharps (Sharpses?) and especially good old Wolfgang.
Here's the carbine #799 that I traded into last weekend, you can perhaps see the wolf's head at right of the photo. Maybe not, though, photo handling with Windows 10 is unreliable.

414284415.jpg

There is a captivating beauty to this carbine and I am afraid said beauty is why I am now rid of a 1954 Garand and an Arsenal AK 74.
-----krinko
 
Status
Not open for further replies.

Similar threads

Griffen
  • Locked
Loading 45 Colt black powder cartridge- need some help
2 3
Replies
64
Views
5K
Dave T
Dave T
D
  • Locked
"Former" for rifled musket cartridges
Replies
6
Views
759
arcticap
arcticap
S
  • Locked
Disproving the myth of "Air Gap is dangerous" for Black Powder Cartridges
2 3
Replies
57
Views
4K
Black cloud
Black cloud
M
  • Locked
Getting Into Reloading with Black Powder - A Few Questions
Replies
15
Views
2K
Mr. D
M
Driftwood Johnson
  • Locked
Shooting Black Powder in Cartridge Guns
2 3
Replies
65
Views
21K
Loyalist Dave
Loyalist Dave
Back
Top