Author Topic: Smokeless in BP Era Cartridge Guns  (Read 8770 times)

Offline PJ Hardtack

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Smokeless in BP Era Cartridge Guns
« on: October 21, 2012, 04:31:13 pm »
The current issue of 'Rifle' magazine has an article on the inherent dangers of shooting smokeless loads in original BP cartridge guns, not just Damascus barrels.
Pressure spikes, too hard bullets causing forcing cone splits, bulged chambers, etc. I've also heard that using smokeless can cause plating to flake off cylinders due to pressure expansion. We all do it, but it pays to know the risks.

One thing the author mentions is the low powder charge phenomenon of detonation that even modern guns do not survive well. It utterly destroys BP era guns.

I had the cylinder of my Tranter .450 Army magnafluxed by a firm that does it for the aerospace industry. It passed with flying colours and I do shoot it with smokeless.

Seems the only safe approach is to shoot them with the original powder ...... ;>)
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Offline Grapeshot

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Re: Smokeless in BP Era Cartridge Guns
« Reply #1 on: October 21, 2012, 06:33:05 pm »
Your right.  I read the article and it dovetails with everything else I've read discouraging use of smokeless in BP era cartridge guns.  The pressure curve is different with Smokeless vs Black Powder.  The sharp BP spike quickly peters out, the Smokeless spike has a longer dwell time and puts more stress on the old steels.  Many good BP pistols have been shot loose using a LIGHT charge of Smokeless.

For those old timers, keep it simple and use BP to stay safe.
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Offline w44wcf

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Re: Smokeless in BP Era Cartridge Guns
« Reply #2 on: October 22, 2012, 07:15:39 pm »
IT WAS A GREAT ARTICLE ABOUT THE WRONG SMOKELESS POWDERS TO USE IN BLACK POWDER ERA GUNS!!!!!

As a matter of fact, factory smokeless powder cartridges for use in b.p. firearms were made available beginning in 1895.
Winchester, UMC, and others thought it was plenty safe to shoot b.p. era guns with their smokeless cartridges.  ;D
They used "low pressure" smokeless powder......unlike what the article referenced.

I was a bit disappointed that the article did not go on to expalain that.

DuPont No 1 Bulk Smokeless was used in 45-70 and like cartridges. DuPont No. 2 Bulk Smokeless was used in the smaller 44-40 and like cartridges.

The burning rate for DuPont No. 1 is similar to 4198, DuPont No. 2, similar to 4227.
In the early 1900's, Sharpshooter displaced the bulk powders and was used in both pistol and rifle cartridges. It's burning rate is close to 2400.  

Here's a typical smokeless box from that era. Note the recommended use in 1873 Winchester rifles......



On the personal side, I own a 1873 Winchester made in 1882. I purchased it 13 years ago and since that time, over 2,000 smokeless rounds have transversed the barrel with no issues whatsoever. I used mostly 2400 and 4227 to propell those bullets.  ;D

Fast forward to today. There is no warning on ammunition boxes not to use current 38-40, 44-40, 45-70 and like cartridges in older b.p. firearms BECAUSE they do not generate any more pressure than the original b.p. cartridges.

w44wcf  

« Last Edit: October 22, 2012, 07:17:31 pm by w44wcf »
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Offline Cemetery

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Re: Smokeless in BP Era Cartridge Guns
« Reply #3 on: October 23, 2012, 04:08:38 pm »
IT WAS A GREAT ARTICLE ABOUT THE WRONG SMOKELESS POWDERS TO USE IN BLACK POWDER ERA GUNS!!!!!

I used mostly 2400 and 4227 to propell those bullets.  ;D

Fast forward to today. There is no warning on ammunition boxes not to use current 38-40, 44-40, 45-70 and like cartridges in older b.p. firearms BECAUSE they do not generate any more pressure than the original b.p. cartridges.

w44wcf  



Since I know not of this mythical powder referred to as 'smokeless'.....where and how would I educate myself on such powder to 'roll my own' for use in my original BP guns?  I don't need the type of 'boom' that would ruin my day.....

also, if I'm following you correctly, if I was to go buy a box of factory made 44.40 or 45.70 right now, it would have no more pressure generating from it, then from made in the 1880's?
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Offline maldito gringo

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Re: Smokeless in BP Era Cartridge Guns
« Reply #4 on: October 23, 2012, 04:57:22 pm »
There are authorities I greatly respect who assert that NO smokless should ever be used in BP era guns. There are authorities I greatly respect who claim otherwise. I stand with the latter group, assuming:
1. The firearm in question is mechanically sound and operating as it should.
2. The yeild strength ( elastic limit ) of the steel gives an adequate margin of safety above the peak pressure developed in the chamber. For instance, decarbonized ( Bessemer process ) steel has published limits from 28000psi to 45000psi. Taking the lower limit and derating by 50% gives a peak pressure of 14000psi or a 1:2 margin of safety.
3. The shape of the pressure curve closely matches the original loading of BP.
Some rely on the relitave quickness of the powder as a guide, but this can be misleading. I have seen comparitave traces for some
"fast" powders under light loads of shot that give lower pressure & gentler curves than BP for equal velocity. In any case, loading up the ol' smokewagon with nitro is not to be done casually. Can it be? I have no doubt. I do it without issue and so do many others.

Offline Trailrider

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Re: Smokeless in BP Era Cartridge Guns
« Reply #5 on: October 23, 2012, 11:46:58 pm »
There is NO WAY that the large ammo manufacturers would dare load such BP cartridges with smokeless if it were not possible to do so with RELATIVE safety. These include .45 LC, .44-40 and .45-70 in particular.  Smokeless powders CAN give a sharper rise in pressure, even if the maximum pressure is the same as BP. HOWEVER...the proper smokeless powder and load can be tailored to spread its pressure/time curve out to make it similar to BP.  I have run such tests comparing certain loads of IMR3031 with Remington factory loads of a similar looking powder and charge weight in Remington .45-70 loads. (NOTE: These Remington rounds were produced some years ago, but within the modern period (1970's). Don't know what they are loading in them now.)

What has to be done is to balance the slowness of a particular smokeless powder with the bullet weight and charge weight so you don't get ignition delays with possible catastrophic overpressures.  This takes special equipment, and even the Oehler M43 PBL can't detect some of the lower-pressure ignition transient signiture phenomenon. And cementing the strain gage on a revolver cylinder chamber can be a real pain!

So, I cannot say CATAGORICALLY that it is safe or unsafe to shoot smokeless powder in BP guns. It can be done. But (a) the gun has to be in good mechanical conditiion; (b) the powder charge has to be carefully developed, and (c) HEAVY, continuous use of antique guns will eventually have a detrimental effect on them, especially if the gun is made of iron, rather than steel, and even if made of steel, depending on the proper heat treatment of the steel to start. So while I have shot a number of antique cartridge guns with smokeless powder in the past, I have retired many of them altogether to preserve them for prosterity.  My CAS guns are modern-made Rugers, Rossi's, etc.

Ride careful, Pards!
Ride to the sound of the guns, but watch out for bushwhackers! Godspeed to all in harm's way in the defense of Freedom! God Bless America!

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Offline w44wcf

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Re: Smokeless in BP Era Cartridge Guns
« Reply #6 on: October 24, 2012, 09:54:21 am »
Since I know not of this mythical powder referred to as 'smokeless'.....where and how would I educate myself on such powder to 'roll my own' for use in my original BP guns?  I don't need the type of 'boom' that would ruin my day.....

also, if I'm following you correctly, if I was to go buy a box of factory made 44.40 or 45.70 right now, it would have no more pressure generating from it, then from made in the 1880's?

That is correct ONLY if it is the Winchester or Remington brand or "Cowboy" ammunition produced by several different company's.

DO NOT USE higher performance or +P ammunition as produced by Buffalo Bore, Grizzly, Corbon etc. since they are loaded to higher pressures.  

As far as "rolling your own", I would suggest picking up a Lyman Handbook.  They have smokeless loads listed for different strength guns for the 44-40 and 45-70.

Have fun!
w44wcf
« Last Edit: October 24, 2012, 09:57:03 am by w44wcf »
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Offline w44wcf

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Re: Smokeless in BP Era Cartridge Guns
« Reply #7 on: October 24, 2012, 10:27:11 am »
maldito gringo, Trailrider,
Thank you for your insight.  The only smokeless powder that I am aware of that gives a pressure spike  even quicker than b.p. is Trailboss based on a comparison graph I have seen. Powders like 2400, 4227 and 4759 have a slower pressure spike than b.p. although perhaps of a slightly longer duration...in milliseconds.

Several years ago I spoke to a ballistics lab technician of many years experience who is now retired and asked about the length of pressure duration on the firearm. He said that in his opinion it was the peak (highest) pressure that was important and the duration made no difference.

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Offline Drydock

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Offline maldito gringo

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Re: Smokeless in BP Era Cartridge Guns
« Reply #9 on: October 24, 2012, 07:58:46 pm »
 A resistor rated for 250VDC can be destroyed at a lower value if the rise time of the applied voltage is too fast for the component
to handle. There may be a corresponding phenomenon in chamber pressure,ie, it's not just the peak presssure developed, it's also how fast it's gettin' there. The steel needs time to expand and contract back to it's original dimensions. This is why the pressure curve
should ideally mimic the curve of the BP load. Of course, we're assuming that the BP load was "safe" to begin with. While the relative quickness of the powder used will have a major effect on the curve, so will the bullet weight, case volume and crimp.  

Offline Driftwood Johnson

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Re: Smokeless in BP Era Cartridge Guns
« Reply #10 on: October 25, 2012, 06:40:08 pm »
Quote
We all do it, but it pays to know the risks.

No, we do not all do it.

However, I think something needs to be said about the relative strength of a revolver vs a rifle. A rifle is just plain inherently stronger than a revolver. There is much more steel surrounding the chamber of a rifle than there is with any revolver. And the breech lockup is going to be stronger with just about any rifle than with a revolver. I do not hesitate to shoot smokeless ammo in my Marlin 1894 or my Winchester Model 1892, both chambered for 44-40 and both made in the 1890s. I keep the loads relatively mild. I use Unique powder.

However a revolver is an entirely different story. No matter what revolver you are talking about, the chamber walls are much, much thinner than with any rifle. And there is no such thing as a breech block with a revolver. All there is is the recoil plate backing up the case head.

For these reasons, I do not hesitate to shoot Smokeless 44-40 loads in my old rifles, and if I owned a vintage '73 ( I keep looking for one) as long as it was in good shape I would not hesitate to shoot my same Smokeless 44-40 loads in it.

However I own several revolvers made before 1900, and I will not shoot Smokeless in any of them. You can shoot Smokeless in your revolvers if you want, but not me. Particularly not with relatively fast modern pistol powders.

As far as pressure curves are concerned, here is one that a ballistics technician sent me some time ago. Yes, the specifics of the powder are unknown. The chart is for two shotgun loads that each developed 1200 fps with 1 1/8 ounces of shot. Notice the pressure spike with the Smokeless load is not only higher, it is much sharper. That is why modern Smokeless powder can hurt old guns. The sharp spike of short duration shocks the metal, and some old steel can't take the shock. Notice the BP curve is not only lower in amplitude, but it is spread out over a longer time. That is why BP is less harmfull to older guns. The pressure is of less amplitude and it is spread out over more time.

I have examined too many old revolvers that are no longer tight. I may be wrong, but I assume that the sharp spike of Smokeless, or too many Smokeless loads, over time, has stretched the frame so that lockup is no longer tight. This can be seen on many Top Break revolvers that no longer latch up tightly.

Nope, only BP for my old revolvers. Rifles are a different story.



« Last Edit: October 25, 2012, 06:42:49 pm by Driftwood Johnson »
That’s bad business! How long do you think I’d stay in operation if it cost me money every time I pulled a job? If he’d pay me that much to stop robbing him, I’d stop robbing him.

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Offline Trailrider

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Re: Smokeless in BP Era Cartridge Guns
« Reply #11 on: October 26, 2012, 12:33:34 am »
Howdy, Driftwood. Been awhile...

I wish I could publish some of the pressure-vs-time curves I've recorded in both rifles and revolvers. Not sure how to do it...but yours shows the relative characteristics of the curves between BP and some smokeless.  Even if the PEAK pressures come out the same, the rate of onset is important, if not critical! I HAVE gotten smokeless loads in .45-70 that were close in profile to BP, but it can be tricky and really requires the pressure measurement equipment to do it right!

There is another hazard with very LIGHT smokeless loads, especially (but NOT limited to) revolvers: That is the danger of a charge so light that the bullet becomes stuck in the FORCING CONE, so that the barrel-cylinder gap is stopped up.  If a charge of smokeless is not ignited completely but the bullet leaves the mouth of the cartridge case, and lodges in the forcing cone, the pressure will increase. Since smokeless powder is progressive-burning, i.e., the higher the pressure, the faster the burning rate, which increases the pressure faster, building on itself. Normally, when a bullet leaves the case and passes down the bore, the pressure drops, slowing the burning rate. But if the bullet stops, so the pressure isn't relieved, the pressure will build up exponentially.  If the pressure in the chamber of a thin cartridge case, like .45 LC and .44-40, builds up past about 35,000-40,000 psi (NOT CUP!), and the chamber is fairly sloppy (as is the situation in many .45 LC, the case may rupture. The resulting escaping gas acts like a cutting torch on the steel. The result is usually the top of the cylinder lifting off, taking the topstrap with it! This can occur in modern-made Colt clones, and even Ruger Old Model Vaqueros, though the later is much less likely to fail catastrophically.

This can occur with medium burning pistol powders that are loaded DOWN to the point where the initial pressure is BELOW 5000 psi.  Ironically, this is less of a problem with some of the faster powders like Bullseye, but you can easily double charge those powders, and the small amount of powder can slop around in the case. That is why Trail Boss was developed, but it isn't a cureall, and I prefer to load that powder NO LIGHTER than the middle load shown in the loading data! It may not be rocket science...butdang near!  (Take it from an old rocket enigneer!)  ;)
Ride to the sound of the guns, but watch out for bushwhackers! Godspeed to all in harm's way in the defense of Freedom! God Bless America!

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Offline rbertalotto

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Re: Smokeless in BP Era Cartridge Guns
« Reply #12 on: October 26, 2012, 07:14:41 am »
FANTASTIC Thread!

Quote
The only smokeless powder that I am aware of that gives a pressure spike  even quicker than b.p. is Trailboss based on a comparison graph I have seen. Powders like 2400, 4227 and 4759 have a slower pressure spike than b.p. although perhaps of a slightly longer duration...in milliseconds.


I was always under the impression that BP had a much slower pressure spike.........I guess you learn something new everyday?

I totally agree about the Rifle vs Revolver issue and using Smokeless. I use mild charges of smokeless in my 1873 and 1889 but would never do the same in a vintage revolver.
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Offline w44wcf

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Re: Smokeless in BP Era Cartridge Guns
« Reply #13 on: October 26, 2012, 07:18:42 pm »
Here's are some  45-70 pressure traces (not mine) that are very telling.
Note the high pressure spike of Trailboss and the higher peak pressure ....faster than even b.p.
Note the much slower pressure rise of 4759 and lower peak pressure .......



w44wcf
« Last Edit: October 26, 2012, 07:22:03 pm by w44wcf »
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Offline Trailrider

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Re: Smokeless in BP Era Cartridge Guns
« Reply #14 on: October 27, 2012, 12:33:38 pm »
Those appear to be pressure traces taken with an Oehler M43 PBL setup, as the data readouts are similar to mine. A number of years ago, I compared the BP trace data with some I did using Remington factory loads with 405 gr Jacketed flat softpoints and some of my own using 395 gr cast bullets, using IMR4198 with both overpowder fillers (1/4" square single ply toilet paper and without). I both instances, the peak pressures (average about 14,900 psi) and the rise (about 122 miliseconds) was LOWER than that for BP!

Interestingly, the BP traces for 35 gr. FFFg GOEX in .45LC showed much sharper rises and peak pressures! Average peak pressure was about 18,300 psi with an average rise of 125.  Using 7.8 gr of Hodgdon's Universal behind a 253 gr hard cast bullet showed sharp peaks of 22,100 psi and a rise time of 139 miliseconds.

I wish I could post the traces, but not sure how to do it on the confuser! If I figure that out, I will do so.
Ride to the sound of the guns, but watch out for bushwhackers! Godspeed to all in harm's way in the defense of Freedom! God Bless America!

Your obedient servant,
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Offline w44wcf

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Re: Smokeless in BP Era Cartridge Guns
« Reply #15 on: October 27, 2012, 07:43:51 pm »
Trailrider,

Interesting! I'm sending you a pm.

w44wcf
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Offline Bryan Austin

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Re: Smokeless in BP Era Cartridge Guns
« Reply #16 on: March 13, 2019, 07:06:21 pm »
Howdy, Driftwood. Been awhile...

I wish I could publish some of the pressure-vs-time curves I've recorded in both rifles and revolvers. Not sure how to do it...but yours shows the relative characteristics of the curves between BP and some smokeless.  Even if the PEAK pressures come out the same, the rate of onset is important, if not critical! I HAVE gotten smokeless loads in .45-70 that were close in profile to BP, but it can be tricky and really requires the pressure measurement equipment to do it right!

There is another hazard with very LIGHT smokeless loads, especially (but NOT limited to) revolvers: That is the danger of a charge so light that the bullet becomes stuck in the FORCING CONE, so that the barrel-cylinder gap is stopped up.  If a charge of smokeless is not ignited completely but the bullet leaves the mouth of the cartridge case, and lodges in the forcing cone, the pressure will increase. Since smokeless powder is progressive-burning, i.e., the higher the pressure, the faster the burning rate, which increases the pressure faster, building on itself. Normally, when a bullet leaves the case and passes down the bore, the pressure drops, slowing the burning rate. But if the bullet stops, so the pressure isn't relieved, the pressure will build up exponentially.  If the pressure in the chamber of a thin cartridge case, like .45 LC and .44-40, builds up past about 35,000-40,000 psi (NOT CUP!), and the chamber is fairly sloppy (as is the situation in many .45 LC, the case may rupture. The resulting escaping gas acts like a cutting torch on the steel. The result is usually the top of the cylinder lifting off, taking the topstrap with it! This can occur in modern-made Colt clones, and even Ruger Old Model Vaqueros, though the later is much less likely to fail catastrophically.

This can occur with medium burning pistol powders that are loaded DOWN to the point where the initial pressure is BELOW 5000 psi.  Ironically, this is less of a problem with some of the faster powders like Bullseye, but you can easily double charge those powders, and the small amount of powder can slop around in the case. That is why Trail Boss was developed, but it isn't a cureall, and I prefer to load that powder NO LIGHTER than the middle load shown in the loading data! It may not be rocket science...butdang near!  (Take it from an old rocket enigneer!)  ;)


This deserves a bump!!! After what I have seen, it certainly makes sense. I posted over on the SASS forum about blown guns and I have never seen so many in one topic. I bet most are because of many undercharged that just couldn't take any more.
https://forums.sassnet.com/index.php?/topic/283467-blown-guns-during-sass-matches/

Offline greyhawk

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Re: Smokeless in BP Era Cartridge Guns
« Reply #17 on: March 13, 2019, 09:10:59 pm »
This deserves a bump!!! After what I have seen, it certainly makes sense. I posted over on the SASS forum about blown guns and I have never seen so many in one topic. I bet most are because of many undercharged that just couldn't take any more.
https://forums.sassnet.com/index.php?/topic/283467-blown-guns-during-sass-matches/

So how does this work ?
The primer force blows the boolit into the forcing cone before the powder charge lights properly then we get a blow like a plugged barrel would ?

Over the years there have been a number of slow powders came with serious warnings NOT to undercharge (Winchester 785 comes to mind) but I never saw a decent explanation of what was going on ? 

Offline Coffinmaker

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Re: Smokeless in BP Era Cartridge Guns
« Reply #18 on: March 13, 2019, 10:03:17 pm »

Greyhawk -- Et ALL.

First a CAVEAT:  I am not a a Ballistician.  Never have been.  Don't even own a Chrono.  I have no clue the pressures of my BP loads not the velocity.  So there.

There is a persistent OLD WIVES TALE which alludes guns can be and are blown up with light loads.  THAT is in fact ..... a non fact.  Smoke and Mirrors.  It is in fact Rocket Science and Physics.  FACT:  There are "X" Jules of energy stored in a given amount of propellant.  As song as that amount of propellant ignites and travels down the bore, a light load contains insufficient stored energy to damage the gun.
PERIOD.  END OF DISCUSSION.  A LIGHT LOAD CANNOT DESTROY A GUN.  Manufactures of Propellants (powder) and the military have been trying for years do catastrophically fail a fire arm with a light load.  NO JOY.  The conclusion ..... A LIGHT LOAD CANNOT DESTROY A GUN.  PERIOD

UNLESS THERE IS A BORE OBSTRUCTION!!!!  If the free expansion of the gun gas is restricted, the gun gas WILL seek a release.  If the cartridge case fails (excessive pressure) the gun gas will seek release (gun gas is really hot) and once no longer retained by the cartridge, the gun gas will cut through the cylinder and head for the fence.   This all takes place in a nano second or two and only when there is an OBSTRUCTION.  The most common obstruction causing catastrophic failure is the inadvertent placement of TWO BULLETS is a single case or having the obstruction occur within the chamber following premature shot start.

So ...... when you see those newbys asking "how low can you go" just stamp their forehead with the 'IDIOT" stamp and walk away.

THE END.  Return to your normally scheduled programming    ;D

Offline greyhawk

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Re: Smokeless in BP Era Cartridge Guns
« Reply #19 on: March 14, 2019, 02:07:12 am »
Greyhawk -- Et ALL.

First a CAVEAT:  I am not a a Ballistician.  Never have been.  Don't even own a Chrono.  I have no clue the pressures of my BP loads not the velocity.  So there.

There is a persistent OLD WIVES TALE which alludes guns can be and are blown up with light loads.  THAT is in fact ..... a non fact.  Smoke and Mirrors.  It is in fact Rocket Science and Physics.  FACT:  There are "X" Jules of energy stored in a given amount of propellant.  As song as that amount of propellant ignites and travels down the bore, a light load contains insufficient stored energy to damage the gun.
PERIOD.  END OF DISCUSSION.  A LIGHT LOAD CANNOT DESTROY A GUN.  Manufactures of Propellants (powder) and the military have been trying for years do catastrophically fail a fire arm with a light load.  NO JOY.  The conclusion ..... A LIGHT LOAD CANNOT DESTROY A GUN.  PERIOD

UNLESS THERE IS A BORE OBSTRUCTION!!!!  If the free expansion of the gun gas is restricted, the gun gas WILL seek a release.  If the cartridge case fails (excessive pressure) the gun gas will seek release (gun gas is really hot) and once no longer retained by the cartridge, the gun gas will cut through the cylinder and head for the fence.   This all takes place in a nano second or two and only when there is an OBSTRUCTION.  The most common obstruction causing catastrophic failure is the inadvertent placement of TWO BULLETS is a single case or having the obstruction occur within the chamber following premature shot start.

So ...... when you see those newbys asking "how low can you go" just stamp their forehead with the 'IDIOT" stamp and walk away.

THE END.  Return to your normally scheduled programming    ;D

Ok thats a logical argument and it makes sense - but I am a bit thick - did your answer above say yes to my theory of the projectile becoming a bore obstruction as the powder stuttered its way alight or was that a NO

if that was yes ignore the next bit

theres always a what if

1) did all the energy get released ?
2) did it get released at the same rate ?
OR is it possible there is a leaner burn thing happening if the powder charge is diluted out in more space as ignition happens
This idea works with petrol, it works with wheat dust in grain silos it works (I am told) with aluminium particles in a large enclosed space - how come it dont work with powder charges??   

ok another tack - diesel ignition in a muzzle loader?
Two fellers out here almost lost a hand in process of loading 38 cal ML match rifles
We was always reared with the idea you held the shaft of the ramrod in case of a blow and if that occurred it would shoot the ramrod out through your fist and all would be well - (except for burned eyebrows and ringing ears) - that didnt work !!!
I know one bloke a bit and seen his hand The 38 slug came out ahead of the ramrod tip in a big long shredded strip that entered the meaty part of the heel of the hand and exited (partly) about the knuckle of the thumb - genius here says "that has got to be diesel ignition in the tube - no other way that coulda happened" not the most popular thing to say at this blokes campfire ...... by elimination - if there was an ember - the powder was already downbore and a card wad over it - it woulda blew already if there was a spark in the barrel - the slug is a false muzzle deal with a greased fully engraved boolit - a real nice sealant - coulda been a oiled felt wad too I didnt ask - only takes 11 to 1 compression to ignite diesel or oil (maybe less would do it) not so hard to do that with a ramrod if ya left the old cap on the nipple and some oil/grease in the bore - everybody is extremely puzzled as to how this could happen - hadda been some dill like me - blame would have easily been assigned but both these guys are top shots in the country so how could they have made a mistake?
I am not gonna get a sneaky lil 38 slug gun to improve my chances in the open ML event !!! 


 

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