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Blown Guns During SASS Matches?


Savvy Jack

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Guessing about 4 years ago, this pistol blew up.  Piece of brass hit the window frame next to my face while spotting.  Bad reloads.

 

The rifle blew up when, I think, a smokeless round was loaded into this old antique lever gun.  Both shooters ended up with some hand injuries.

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one colt clone, found part of the cylinder stuck in a prop one or two bays away,,  May have been the same one Yusta B saw,,,

 

only blow up I've seen,,, lots of bulged barrels and such tho.

 

In my experiences, most OOB have nothing to do with the lever safety,,,

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10 hours ago, Shooting Bull said:

 

I know this is a serious subject but THAT'S funny. :lol:

 

I have a page from an Army manual on my wall at work.   Definition of explosion---a loud noise followed by the sudden disappearance of things that were there a second ago!

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4 hours ago, Trailrider #896 said:

Quite awhile back:  Original New Model #3 S&W in .44-40.  Shooter used some ammo he got from an "amateur" handloader!  First two rounds barely made it ten feet from the muzzle.  Third round blew the cylinder and top strap.  I was NOT allowed to examine either the gun or the remaining ammo.  With those two near-squib loads, it might have been "premature shotstart" with the bullets not retarded against movement until the smokeless powder came up to stable ignition. With the bullet out of the case and into the forcing cone before pressure buildup, pressures would have gone out of case rupture strength.  Other possible cause: double charge.  Pity, there weren't that many .44-40 NM#3's made!

 

Second case was a Colt's clone, .45LC.  Blown cylinder & top strap departed.  Examined remaining ammo, and found very little crimp and tension on the bullet by the case.  Probable cause, as mentioned above, premature shotstart with the bullet lodging in the forcing cone before the rest of the charge started burning steadily,  Once the bullet stuck, it requires a great deal more force to get it moving again.  Remaining powder then takes off and brass can't handle the pressure, ruptures, allowing flame to cut the chamber walls, and off goes the top of the gun.  Moral on that one: be sure to have enough case tension on the bullet (don't over expand the case mouth), and CRIMP! CRIMP! CRIMP!  Use a roll crimp!

 

Really would like to know what powder was in those loads,

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Two:

* A Remington NMA with a top strap that looked like Mt Everest

* Mine - Old Model Ruger Vaquero, 45 Colt - spilt web between 2 cylinder throats - with black powder

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Not a blown up gun, but a Pard of mine dumped a live shell out of his shotgun, it hit a pebble it something just right and fired the shell. Nobody hurt, but scared the bejeebers out of him. 

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22 hours ago, Savvy Jack said:

Ever notice the cylinder lock is center chamber on these? That makes for one hell of a weak spot compared to Colt's off-set cylinder lock location. 

 

 

Howdy Again

 

Not so much as you might think.

 

Here is another Merwin Hulbert cylinder. Yes, the locking slot for the bolt is pretty much centered on the centerline of the chamber, right where the web is the thinnest.

 

Merwin%20Hulbert_zpsui3reju9.jpg

 

 

 

 

Here is a S&W New Model Number Three cylinder. Again the locking slot is pretty much centered on the centerline of the chamber.

 

New%20Model%20Number%20Three_zpswmp04rny

 

 

 

 

Here is a 2nd Gen Colt. yes, you can see the locking slot is off center from the chamber centerline.

 

Colt%202nd%20Gen_zpsdnphdnf4.jpg

 

 

 

But take a look at a dimensioned cross section of a Colt 2nd Gen cylinder from Kuhnhausen's Colt Single Action Revolvers, A Shop Manual, Voulumes 1 & 2.

 

Notice how one edge of the cut is only .010 away from the centerline. Notice too how little metal is left between the chamber and the bottom of the cut. I don't have a measurement for a 45 Colt chamber in a Colt, but I'm pretty sure there is only a few thousandths of metal between the bottom of the slot and the chamber wall.

 

Kuhnhausen%20Colt%20Cylinider%20Cross%20

 

 

 

Here is the real champion of off setting a locking slot from the centerline of a chamber. This is a Ruger New Vaquero, chambered for 45 Colt. I don't have an actual measurement, but you can compare this photo to the Colt cylinder and see how much further off set from the centerline the locking slot is in the Ruger. All Rugers are like this, even the old Three Screws.

 

Ruger%20Vaquero_zpsldxihlpw.jpg

 

 

 

 

What these photos of the blown Merwin Hulbert cylinder do illustrate is exaclty how a cylinder usually bursts. The failure started at the locking slot, clearly the thinnest cross section of the cylinder. Then the failure propagated along the thinnest part of the web between chambers. Note too that the two chambers adjacent to the one that failed almost failed too. Note how the metal folded right at the locking slots. A little bit more oomph and the adjacent two chambers would have failed too.

 

This also illustrates how the cylinder is the weakest part of almost all revolvers. An over pressure event will almost always burst the cylinder, rather than the barrel, because the cross section of the barrel is much thicker than the cylinder walls.

 

blownmerwinhulbertcylinder02_zpsd6b45aad

 

blownmerwinhulbertcylinder01_zpse057ebd4

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1 hour ago, Sedalia Dave said:

 

Really would like to know what powder was in those loads,

In the first incident...so would I!  Unfortunately, the shooter turned the gun and the remaining cartridges over to...the police! While I have great admiration for those in blue who put their lives on the line for us, I don't have a great deal of confidence in their ability to analyze an incident such as these...not without a lot of lab equipment and experience.

 

In the second incident, I was able to not only examine the gun and remaining cartridges, but sent some to Hodgdon's for analysis.  The analysis of both my own and Hodgdon's as to insufficient bullet pull was written up in my book, "Trailrider's Guide to Cowboy Action Shooting", Pioneer Press (Dixie Gun Works), 1998.  The shooter stated that he loaded each round on a single-stage press, and checked for double charges, though he could not swear for certain that he checked every case, although his teenage son was assisting him in the loading process.  The charge was 7.8 gr, Hodgdon's Universal behind a 250 gr.  According to Hodgdon's a double-charge would produce about 52,000 psi, which definitely would disassemble a Colt's design gun.  But a double-charge of this powder and weight would probably have been evident.  Again, the probable cause is likely to have been insufficient bullet pull allowing the bullet to be propelled into the forcing cone, followed by the smoldering powder coming up to progressive burning, with the pressures exceeding the ultimate tensile strength of the case, followed by flame-cutting of the cylinder wall, combined with the rapid energy release.

 

[Note: This is not a solicitation for the sale of the above-mentioned book.  Dixie Gun Works may have copies left in stock; I do not!] 

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4 hours ago, German Jim said:

Guessing about 4 years ago, this pistol blew up.  Piece of brass hit the window frame next to my face while spotting.  Bad reloads.

 

The rifle blew up when, I think, a smokeless round was loaded into this old antique lever gun.  Both shooters ended up with some hand injuries.

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Jim - That appears to be a M1886 Winchester.  Whatever the load was (most likely a smokeless powder, note that the action doesn't appear damaged (except maybe the threads).  Obviously, the pressures were sufficient to blow out the chamber allowing hot gases to escape into the forearm area.  Most likely the handload was a double-charge or the wrong choice of propellant.  But the receiver design is one of John Moses Browning's masterpieces. Except for using nickel-steel barrels, the design of the action itself made the transition to the 20th Century, chambered for the .33 WCF, and with slight modifications to the M71 chambered for the .348 WCF!

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8 hours ago, Driftwood Johnson, SASS #38283 said:

 

 

Howdy Again

 

Not so much as you might think.

 

Here is another Merwin Hulbert cylinder. Yes, the locking slot for the bolt is pretty much centered on the centerline of the chamber, right where the web is the thinnest.

 

8 hours ago, Driftwood Johnson, SASS #38283 said:

 

 

Howdy Again

 

Not so much as you might think.

 

Here is another Merwin Hulbert cylinder. Yes, the locking slot for the bolt is pretty much centered on the centerline of the chamber, right where the web is the thinnest.

 

Merwin%20Hulbert_zpsui3reju9.jpg

 

 

 

 

Here is a S&W New Model Number Three cylinder. Again the locking slot is pretty much centered on the centerline of the chamber.

 

New%20Model%20Number%20Three_zpswmp04rny

 

 

 

 

Here is a 2nd Gen Colt. yes, you can see the locking slot is off center from the chamber centerline.

 

Colt%202nd%20Gen_zpsdnphdnf4.jpg

 

 

 

But take a look at a dimensioned cross section of a Colt 2nd Gen cylinder from Kuhnhausen's Colt Revolvers Single Action Revolvers, A Shop Manual, Voulumes 1 & 2.

 

Notice how one edge of the cut is only .010 away from the centerline. Notice too how little metal is left between the chamber and the bottom of the cut. I don't have a measurement for a 45 Colt chamber in a Colt, but I'm pretty sure there is only a few thousandths of metal between the bottom of the slot and the chamber wall.

 

Kuhnhausen%20Colt%20Cylinider%20Cross%20

 

 

 

Here is the real champion of off setting a locking slot from the centerline of a chamber. This is a Ruger New Vaquero, chambered for 45 Colt. I don't have an actual measurement, but you can compare this photo to the Colt cylinder and see how much further off set from the centerline the locking slot is in the Ruger. All Rugers are like this, even the old Three Screws.

 

Ruger%20Vaquero_zpsldxihlpw.jpg

 

 

 

 

What these photos of the blown Merwin Hulbert cylinder do illustrate is exaclty how a cylinder usually bursts. The failure started at the locking slot, clearly the thinnest cross section of the cylinder. Then the failure propagated along the thinnest part of the web between chambers. Note too that the two chambers adjacent to the one that failed almost failed too. Note how the metal folded right at the locking slots. A little bit more oomph and the adjacent two chambers would have failed too.

 

This also illustrates how the cylinder is the weakest part of almost all revolvers. An over pressure event will almost always burst the cylinder, rather than the barrel, because the cross section of the barrel is much thicker than the cylinder walls.

 

blownmerwinhulbertcylinder02_zpsd6b45aad

 

blownmerwinhulbertcylinder01_zpse057ebd4

 

 

 

 

Here is a S&W New Model Number Three cylinder. Again the locking slot is pretty much centered on the centerline of the chamber.

 

 

 

 

 

 

Here is a 2nd Gen Colt. yes, you can see the locking slot is off center from the chamber centerline.

 

 

 

 

 

But take a look at a dimensioned cross section of a Colt 2nd Gen cylinder from Kuhnhausen's Colt Revolvers Single Action Revolvers, A Shop Manual, Voulumes 1 & 2.

 

Notice how one edge of the cut is only .010 away from the centerline. Notice too how little metal is left between the chamber and the bottom of the cut. I don't have a measurement for a 45 Colt chamber in a Colt, but I'm pretty sure there is only a few thousandths of metal between the bottom of the slot and the chamber wall.

 

 

 

 

 

Here is the real champion of off setting a locking slot from the centerline of a chamber. This is a Ruger New Vaquero, chambered for 45 Colt. I don't have an actual measurement, but you can compare this photo to the Colt cylinder and see how much further off set from the centerline the locking slot is in the Ruger. All Rugers are like this, even the old Three Screws.

 

 

 

 

 

 

What these photos of the blown Merwin Hulbert cylinder do illustrate is exaclty how a cylinder usually bursts. The failure started at the locking slot, clearly the thinnest cross section of the cylinder. Then the failure propagated along the thinnest part of the web between chambers. Note too that the two chambers adjacent to the one that failed almost failed too. Note how the metal folded right at the locking slots. A little bit more oomph and the adjacent two chambers would have failed too.

 

This also illustrates how the cylinder is the weakest part of almost all revolvers. An over pressure event will almost always burst the cylinder, rather than the barrel, because the cross section of the barrel is much thicker than the cylinder walls.

 

 

 

 

Driftwood that is an excellent post!!! This has been my theory recently and you posted some excellent comparison photos. I do believe this is exactly why the week link for the 44-40 firearms is the black powder era "pistols" rather than the Winchester toggle link. In 1895 when Winchester offered smokeless powder for the 44-40, the Box labels were red and noted for The Winchester 73' but not for use in Revolvers!!! Those photos clearly show that the Merwin Hulbert could be the weakest but your certainly nailed it, the Colt cylinder doesn't look much stronger, but stronger nonetheless!!

Do you mind if I use your post on the 44 Center Fire Cartridge web page?

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Some 40 years ago, Sketter Skelton took a S&W 28 Highway Patrol 357 Magnum and replaced the barrel with a 45 from a 25 target.  Then had the cylinder rechambered  to 45 Colt.  I did one myself.  Had a guy in the northeast recut the cylinder.  But in Sketter's articles,  he noted that the metal was very thin at the bolt cuts.  In fact,  some were known to be cut through.  He didn't see this as a problem. 

 

I wish I'd waited.  His conversion started intrest in 45 Colt double actions and Smith and Wesson started offering their 25s in 45Colt.  The Highway Patrol cylinder was too short to load a full length 45Colt round. 

 

5ad119e20d3a1_SW25-5April2018.jpg.101343ccbce5392d6e59ff5aa371218e.jpg

 

Armoloyed 25 in 45Colt.  I past it on to youngest son last fall.  He wanted something for badkup when packing out elk, etc out in bear country. 

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I only remember seeing 2 in the 20 odd years I've been shooting cowboy.  Both were Colt clones, with the same shooter who was using his brother in  law's reloads.  The guns blew up only a couple of matches apart and were probably due to a double charge, although I did not examine the guns or ammo.  I do remember parts of the cylinder landing near me and I was probably a good 10-15 yards behind the shooter.  I don't recall anyone being injured.

 

While I am always willing to loan a shooter a gun to shoot if needed or to try out, they can only use factory ammunition or my reloads in my guns.  I will not allow shooters to use their reloads in my guns.

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Yeap, looks like those pistol powders in large volume cowboy cartridges are eating people's lunches!!

Happened to me too what I first started shooting SASS. Too low a load caused a few squibs, I stopped right there and switched to BP. Later to Trail Boss

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Here's the only pic I have of the Walker I blew up a few years back. Black powder, 285 conical. I may have loaded 4f by accident, I may have forgot to lube the bullet, it might have just been one of those things, I just don't know.

 

I will tell you this, it scared the crap put of me!

WALKERKILLED_zps61c19a11.jpg

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4 hours ago, Savvy Jack said:

Do you mind if I use your post on the 44 Center Fire Cartridge web page?

 

First, can you give me a link to that web page?

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I split a barrel on a Pietta 1860 revolver.  Never came up with a cause.  It really did not bother me as I completed the next stage in 119 seconds, clean.

Bulged a barrel on a Uberti 1866. Again, no cause ever determined

Saw a 12 ga double disassembled by firing a 12 ga. shell over a barrel obstructed with a 20 ga round.

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We spend an inordinate amount of time and $$ on our beloved firearms so if you think you've had a squib, STOP!!! You're gonna want to trust me on this.

Italian clone with a squib; no one called the squib but I should have stopped. With the amount of frustration mounted since this happened trying to replace the barrel (7 1/2 in. with a split), I would have gladly taken ANY penalty or delay for that match (or any match) to have the use of my Remmie back. It is now a lovely paperweight. Crap does happen; shoot long enough and you will see. Take your time, be careful and hopefully it won't be you.

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Guest Texas jack Black SASS#9362

This is why I load only gallery loads for my SASS guns  Light lead and light powder charges 

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22 hours ago, Hoss said:

Not a blown up gun, but a Pard of mine dumped a live shell out of his shotgun, it hit a pebble it something just right and fired the shell. Nobody hurt, but scared the bejeebers out of him. 

Interesting. I wonder how frequently that happens, as it is very common for double shooters to load two to take down one KD. Then they shuck both.

 

It also reminds me of the time a double shooter did what I mentioned, shucked a live and an empty round. He then chastised me for tossing him the live round that he just shucked. :o

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We've been shooting CAS for eight years and we had our 1st squib during a match last week.  Bullet did clear the barrel, barely, and TO spotted it.  We have experienced an out of battery that bent the lever a little bit, and have had a round open a double barrel shotgun before the second shot.  Pretty good for the amount of shooting we do.   Never have witnessed a firearm blow up and cannot recall any of our friends having a problem.    

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I've had two squibs in six years, no blow-ups.
But the rifle squib was being rodded out by a helpful other shooter, and caused an OOB on the lifter of my 73.
People, *unload* the gun before you go pounding on it!
My pistol squib was caught right away by the TO.
No damage to any people or guns, but I had to pull some scrap brass out of my boot.
 

1squib.JPG

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I ran a test today. For those that use a light loads of Unique, JUST AS AN EXAMPLE.....

 

Today I tested 12gr of Unique in my 44-40 MGM 1 1/4" diameter 20" "testing" barrel.

200gr Magma 
5 Shots, 2 1/2" Group @ 100 yards
1,635fps @ 21,786 psi,  That could be upwords to 25,000cup, which is mid 44 Magnum pressures with a 200gr bullet.
So there ya go, if you load 6gr for CAS, expect problems with an accidental double charge. If you load 7gr and get a double charge, say good-by world!

When I first started CAS I inadvertently loaded only 4gr of Unique and got two squibs. I shut down for the rest of the day. Used Trail Boss ever since.

Thanks for sharing folks!!!!!

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2 hours ago, Savvy Jack said:

Today I tested 12gr of Unique in my 44-40 MGM 1 1/4" diameter 20" "testing" barrel.

 

You have a pressure testing barrel?

 

I'm impressed.

 

 

Here is one of my favorite photos, the late Barrister Bill with a bullet that did not quite make it out of the barrel. Good thing he stopped in time.

 

Barrister%20Bill%20wimpload%20Scituate%2

 

 

 

 

I must confess I did have a squib in my Henry a few years ago, and fired another round.

 

I shoot Black Powder in my 44-40 Henry. Somehow (dumbass) I managed to load one with no powder in it.

 

When I pulled the trigger, with my ear plugs in I did not hear the primer go off, so I thought it was a bad round, and ejected it. My pard Wild Bill Blackerby over on the loading table heard the primer go off, but I didn't.  When I got my brass back, I expected to find a live round, but there was none to be found. So I examined the bore and there was a slight ring in the barrel down near the frame. So the second bullet must have struck the stuck one and they both went down range. I was probably lucky that

 

1. The octagon barrel of the Henry is pretty thick, and

2. It was a Black Powder load, so a huge amount of pressure was not developed.

 

Despite the slight ring down near the frame (it cannot be felt from the outside) accuracy is still fine from the Henry.

 

Not saying that is the only answer, these days if I don't hear a BOOM I stop and figure out what went wrong.

 

At least that is my plan, I have not not heard a BOOM yet, but if I do, that is my plan.

 

P.S. Thanks for the mention of the blown revolver barrels. Goes to show that my smug theory of the cylinder always blowing first does not always hold water.

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I am a member of a gunsmith group on FB. One guy had pictures of a modern double action that had a squb load bullet stuck in the barrel.  The owner continued shooting the rest of that cylinder and reloaded and shot some more until one couldn't make it out of the cylinder locking up the gun.   He was dumb but persistent! 

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Guest Texas jack Black SASS#9362
2 hours ago, Driftwood Johnson, SASS #38283 said:

 

You have a pressure testing barrel?

 

I'm impressed.

 

 

Here is one of my favorite photos, the late Barrister Bill with a bullet that did not quite make it out of the barrel. Good thing he stopped in time.

 

Barrister%20Bill%20wimpload%20Scituate%2

 

 

 

 

I must confess I did have a squib in my Henry a few years ago, and fired another round.

 

I shoot Black Powder in my 44-40 Henry. Somehow (dumbass) I managed to load one with no powder in it.

 

When I pulled the trigger, with my ear plugs in I did not hear the primer go off, so I thought it was a bad round, and ejected it. My pard Wild Bill Blackerby over on the loading table heard the primer go off, but I didn't.  When I got my brass back, I expected to find a live round, but there was none to be found. So I examined the bore and there was a slight ring in the barrel down near the frame. So the second bullet must have struck the stuck one and they both went down range. I was probably lucky that

 

1. The octagon barrel of the Henry is pretty thick, and

2. It was a Black Powder load, so a huge amount of pressure was not developed.

 

Despite the slight ring down near the frame (it cannot be felt from the outside) accuracy is still fine from the Henry.

 

Not saying that is the only answer, these days if I don't hear a BOOM I stop and figure out what went wrong.

 

At least that is my plan, I have not not heard a BOOM yet, but if I do, that is my plan.

 

P.S. Thanks for the mention of the blown revolver barrels. Goes to show that my smug theory of the cylinder always blowing first does not always hold water.

I remember that day Bill was a very happy cowboy his Colt was safe.

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2 hours ago, Driftwood Johnson, SASS #38283 said:

 

You have a pressure testing barrel?

 

It is just a strain gauge attached to an MGM barrel but the results are reasonably accurate, however are generally not published by many "companies" that use it as they are not as reliable as the CUP and Piezo methods. Reason being one has to use a known pressure. My tests have been surprisingly consistent. Even if my results are not exact, the difference between my loads and the "control" are extremely consistent. In other words, as long as my loads are equal to or lower than the control, all is good. Hint...Winchester factory loads is not my "control" ;-)
The following is from a reputable handloader I will not name. 

 



 

Quote

"44-40 pressures,

 

SAAMI barrels have minimum chambers and nominal bore dimensions. To mimic one, you have to get a barrel blank made to their bore cross-sectional area dimensions and then chamber it with a special reamer ground to produce the SAAMI minimum chamber diameters and not run it in past half a thousandth beyond what produces SAAMI minimum headspace. That's ±¼ of a thousandth, which can take some skill to do. Standard reamers are commonly made a little wider so they can be resharpened without losing dimensional precision. Denton Bramwell points out in the article[Link] most chambers made with standard reamers can expect to produce lower numbers.

SAAMI test barrels are fired with the cartridge manipulated to ensure the powder has fallen back over the flash hole. They are not tapped against anything to do this, as that packs the powder which can lower its burn rate a little. They want worst case highest pressure, so they just turn the case around to let the powder fall back to the rear, then load it carefully so as to avoid shifting the powder position. If you don't do that, you will get lower numbers than they do.

For rifle cartridges, SAAMI expects no more than 4% standard deviation in pressure. If your readings produce a higher SD than that, you are probably using a sample too small to be relied on to produce a good SD number. SAAMI uses ten rounds. Our own board member, xxxxx, who is a professor of statistics, says 30 rounds are needed. Denton Bramwell feels 15 rounds give him what he needs to know. So, why does SAAMI just use 10? They accept the SD results produced by 10 can be off on the high side by two standard errors (about another 2.5%), so they have a second number in addition to the MAP called the Maximum Probable Lot Mean, or MPLM, that allows the next sample of 10 from the same lot could produce a standard deviation that was different by that much. So, while the MAP is 11,000 psi, [44-40] they allow they might get an average as high as 11,300 psi from another random sample of 10 from the same lot, and that is acceptable. They have a still higher number, called the Maximum Probable Sample Mean (MPSM) that allows that bullet bonding with the case and other factors can produce an increase in pressure as a lot of ammunition ages, and for the 44-40 that number is 11,700 psi. So, in effect, they are saying 11,700 psi is the safe limit, but, wait, there's more: All those numbers, the MAP, the MPLM, and the MPSM are averages produced by 10 round samples. The individual rounds making up that average will go above and below that average. SAAMI controls that by allowing what they call the Maximum Extreme Variation (MEV) which is the maximum spread between pressure readings for any of the 10 rounds in any sample taken at any time in the life of the lot. For the 44-40, the MEV is 2300 psi (this has to be calculated per the standard's instructions; it is not in a table). Theoretically, you could have aged loads centered on 11,700 psi whose 10 shots had one round as high as 13770 psi that would still be acceptable to SAAMI (though it is extremely improbable as it requires all 9 other shots to be exactly 11,470 psi). Mostly, though, you don't see individual rounds more than about ten percent above the MAP.

Even with all of that care, the fact is the absolute pressures are not exactly knowable. SAAMI reference cartridges are made in lots that are sent around to member's test facilities every two years to watch for reading changes. The members use SAAMI standard calibration methods (see the SAAMI standard) and report their results for both pressure and velocity from SAAMI standard test barrels. Interestingly, these vary more than the SAAMI standard deviation limit. The old 1992 standard gave an example for each method firing the same lots of reference loads, and the copper crushers, using targe tables for calibration, produced over 23% difference in average pressure for 10 shots among 9 labs. The transducers, using hydraulic pressure for calibration, produced over 11% difference in 10-shot averages among 7 labs. The reported results for each set of tests from each lab were, in turn, averaged and the final average was declared to be the pressure value that reference lot produced. This way, in effect, the reference lot pressure in the example was evaluated by looking at 90 and 70 total sample shots for the crusher and transducer, respectively. It compensates for average measurement calibration and operation errors, combined, to give a practical expected correct reading.

That approach may seem a bit tenuous, but understand the objective is to get everyone producing ammunition to the same standard, even if its absolute accuracy is not perfect. When a manufacturer wants to load a million rounds in a particular chambering, he buys a sample of a current lot of reference ammunition for that chambering and fires it in his own test equipment and compares his results to its agreed-upon rated pressure. This gives him a calibration factor for correcting his equipment's output to match the average output produced by the rest of the test labs that measured the lot. In the end, he doesn't load to the raw pressure readings his equipment provides, but to pressure readings corrected by what the reference load told him was his equipment's error factor.

So, if you wanted to compare strain gauge results to commercial equipment, one would ideally get some SAAMI reference ammunition to calibrate to. Unfortunately, reference ammunition is only sold to ammunition makers or others who can show a real need to have it. Otherwise, I think, they fear a run on it would occur that could interfere with the industry.

I notice all Hodgdon's psi-rated loads for the 44-40 exceed the SAAMI MAP, while their CUP-rated loads (in their pistol section) do not. Makes me wonder if someone confused the digits? It's still below the CIP's pressures, but those are measured on a different style of transducer (a channel transducer).

Regarding CUP ratings in manuals, while the correlation between CUP and psi is too poor for reliably converting one unit to the other over a range of chamberings, within a single chambering the conversion by the ratio of the CUP and psi maps within the SAAMI system is going to be close enough for practical work. That is, 11000 psi divided by 13000 CUP is 0.846 psi/CUP for the 44-40, so you can take the CUP numbers in the Lyman Manual and multiply them by 0.846 to get a reasonable expectation of psi. Conversely, dividing psi by that same number will come close to CUP."

 

Attached is a photo from this morning.

50625366_1096334217213827_8650990902187130880_n.jpg

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What may blow some's minds here would be my 44-40 full Swiss FF black powder loads in certain semi-balloon head cases that produce 14,000psi while Goex FFF produced 12,000psi...same loads in modern brass (with even greater compression) produced between 8, 000 - 11,000 psi depending on what cases I was using....i.e. Starline, Winchester and RP. Western's Semi-balloon head brass gave me the highest (exceeding SAAMI max) psi results followed by WRA and REM-UMC (which were at or just below SAAMI max). Modern brass gave me results up to 25% lower psi than SAAMI max.

Could shed some light on why early 44-40 smokeless powder loads were NOT to be used in black powder frame revolvers and could be why SAAMI's max psi is 11,000psi rather than maybe 13,000-14,000psi. Food for thought....

 

sorry I started rambling!

These are my results and I could be wrong ;-)

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Chance Ramsey blew up two open tops at yesterday’s match with the Lake County Pistoleros.  As I understand it they were 38’s loaded with black powder.  He was shooting BP Gunfighter and blew up the guns with his first two shots.  He os a very experienced shooter and reloaded.  He told me that he was absolutely sure that there was no smokeless powder any where near where he was loading.  He was using a single stage press and dipping the powder with a calibrated dipper.

 

I have no idea how all this could be the case and still blow up both pistols on consecutive shots.  I wouldn’t have thought that you could get enough BP in a 38 case to blow up a gun (much less two guns).  I don’t know what weight bullet he was using, but assume it was 158 gr.

20190119_132524 3.jpg

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