BP 45 colt round compared to modern loadings

[GaryED50]

If this has already been posted Mods please delete but

How different is the Saami pressure curve for the original 45 colt BP round compared to the modern smokeless loading?

Reason I'm asking is on a episode of Pawn Stars they had a Black Powder SSA peacemaker Screw retained cylinder pin and everything, which they fired modern loads in

Gary

[g.willikers]

It shouldn't be too hard to duplicate the original BP load with modern components.
Not the load for modern revolvers, but suitable for the old ones.
The gun experts for the show know their stuff, regardless of the goofy antics of the show's cast.

[Magnum Wheel Man]

a really bulky powder ( like Trailboss ) can often be substituted at safe levels... I use Trailboss to load several black powder cartridges, like 32 S&W, 38 S&W, 44 American Bulldog, 45 Colt, & my newest 45 BPM... I've found that I can get safe load pressures with good ignition & a clean burn, with roughly a half case full of powder, however often the bullet velocity is less than it would be for black powder... but safe to shoot none the less... a cartridge as popular as 45 Colt, has many low pressure loads available

[Kappe]

a really bulky powder ( like Trailboss ) can often be substituted at safe levels...

NO.

Trail Boss is one of the absolute worst powders you could possibly use for blackpowder-era guns. It is almost the exact opposite of BP.

BP is very pressure efficient. It produces surprisingly high velocities for very low pressures. Trail Boss is incredibly inefficient. It produces shockingly high pressures for pathetically low velocities.
Yes, it's generally impossible to exceed SAAMI pressures with Trail Boss without overflowing the case. But that doesn't matter.

Trail Boss is a very fast burning powder with a sharp pressure curve similar to other pistol powders like Bullseye and Unique. BP has a much more rounded pressure curve.
Equivalent pressure doesn't mean diddly squat because the pressure is applied totally differently.

Trail Boss is designed for CAS shooters using modern guns. NOT as a BP substitute for vintage guns.

There are ways of loading smokeless ammunition that is safe for old guns, but it involves slow burning powders like IMR-4227 and 2400.
It is a very advanced and complicated study of handloading, which is why it's just best to say "no smokeless in BP guns".

[Magnum Wheel Man]

gee... I guess I'm doing something wrong... all 4-5000 loaded rounds I have for antique guns...

I did not say it was efficient, or could provide equal velocities... but it can safely ignite with very low charges, within the pressures produced by a case full of black powder, often at marginal velocities, but can be loaded at similar "pressures"

[Kappe]

If you have any published data about loading smokeless cartridges for blackpowder-era guns, I'd like to hear it.

My Lyman handbook in every single blackpowder origin cartridge section (i.e. .44-40, .45-70) states "this data should not be used in firearms originally designed for use with black powder" or a line similar to that.

[GaryED50]

I've always been told and read that black powder firearms used materials, Older types of steel and Iron that can't handle the pressure of Smokeless powder. Which is why the scene on the show shocked me

Gary

[Jim Watson]

Even in the 19th century, the old wrought iron guns had a good deal of safety margin. So called "modern" smokeless loads in calibers that might somehow find their way into an old gun are really pretty light. That was ok for shooters for some time, but the lawyers are now involved and there have to be warnings about every little thing.

I shot some smokeless .44 Russian, .38 S&W, and .38-44 Target. Not a lot, but the guns did fine. One of the leading old S&W gunsmiths says not to. Several owners say they have no trouble even with extended shooting.
I took the safe way out and sold my old guns to collectors. Some people use theirs.

[Magnum Wheel Man]

also... there were a lot of the gun brands made back then, some of better quality than others... also guns of this era ( even the better brands ) had large tolerance spans both over & under in what was acceptable... so consequently some had tighter than they should have been, barrels & throats, some of these guns were unsafe to shoot ( even with black powder ), when new... also as these guns got older, ( & used ) if they weren't cleaned right away, or correctly, the chambers & or barrels ended up pitted from corrosive ammo, thinning chamber walls, & increasing resistance of bullets going down the barrel... so the lawyers jump in, because "Joe Average" pulls out grandpa's old shot loose & ill cared for Colt 45, with chambers worn & barrel pitted, loads up a hard cast bullet at maximum "safe" pressures in the manual, & cracks a cylinder... he's not happy about wrecking a "priceless" family heirloom

I always slug the chamber, throats, & barrel, inspect timing, inspect for excessive pitting in the chamber or barrel, but even if there is pitting noted, if the rest of the gun functions, I have loads safe to shoot in them ( yes, using Trailboss ) & if need be, a soft lead round ball... on some guns, these may be shot at BB gun velocities, but Trailboss by design, works with as little as 0.5 grains in the smaller cases like 32 S&W... you'll note that most powders in the load manuals don't recommend going lower than a certain charge... I've found Trailboss safe with what I call "revolver check out loads" with only a pinch of powder & a soft lead round ball seated

BTW... I have a collection of 40 or so antique guns, that must be shootable to stay at my house... some guns like my old bottom break S&W in 32 RimFire, have yet to be fired, but it does function ( if it were a center fire, & thus reloadable, I'd be shooting it, but as a rim fire, I've not tried pulling bullets & replacing the black powder charges, or cutting the nose off the bullet, to lighten the projectile weight... MRS. MAG really likes shooting the better quality 32 S&W's no noise or recoil, & a bit of history

[Driftwood Johnson]

Howdy

First off, the Pawn Stars 'expert' an idiot. If it is the same episode that I saw a few years ago, he made the classic mistake of lowering the hammer from the half cock loading position. Anybody who knows anything about Colts knows you never do that, you always bring the hammer all the way back to full cock before lowering the hammer, to reset the bolt so it does not bear on the cylinder. He did something else dumb with the gun while still in the shop, but I can't remember now what it was. Clearly, he is not an expert on the SAA.

One of my favorite reference books, Jerry Kuhnhausen's Colt Single Action Revolvers Shop Manual categorically states that Single Action Army revolvers made before 1900 should never be fired with Smokeless powder. Colt did not factory warranty the SAA for Smokeless powder until 1900.

The modern transverse cylinder base pin started being phased in in 1892 and became a standard production feature around 1896. While a few 1899 guns have been found with the old screw type retainer, pretty much any SAA with the screw would have been made before 1900, and therefor not warrantied by Colt for Smokeless Powder.

Cylinder and frame materials for the first SAA revolvers made in 1873 were malleable iron, not steel. From about 1883 until mid 1898 cylinders and frames were made from transitional low/medium carbon steels. By 1900 improved techniques of heat treating cylinders and frames resulted in Colt feeling confident enough to factory warranty the SAA for Smokeless Powder.

It is not just how high the pressure is. The duration of the pressure curve also has an effect on how well the steel will stand up to the pressure. Think about how you might be able to pull a stalled car with a rope tied to the bumper if you accelerate slowly and evenly, but if you pop the clutch most likely the rope will break. Most Smokeless powders, including Trail Boss, have a much sharper pressure spike than Black Powder does. The sharp buildup and fall off of pressure can shock the old metal, causing it to fail, while the slower building pressure curve of Black Powder is kinder to the old metal. That is what Kappe was talking about when he mentioned slow burning powders. The old bulk powders common at the turn of the Century were designed to duplicate Black Powder pressures, including the pressure curve. Modern powders commonly used for Pistols and Revolvers do not do this, they generate an intense, sharp pressure curve.

Most old guns have probably been fired with Smokeless powder loads at some point. That does not mean it is a good idea.

Personally I never shoot any of my old Smith & Wesson pre-1900 revolvers with Smokeless, I only use Black Powder. I don't have any pre-1900 Colts (yet). If I did they would only see Black Powder too.

[radom]

most smokless loads have a lot slower pressure curve than BP unless its trailboss. Thats is pretty much a nanny myth when you look at factual lab tests vs myths. pulling a car on a rope vs gun loads is just silly vs lab tests. Plus the idea that most smokless powder has a higher pressure curve than smokeles is just ahh uneducated as any labortory tests will show otherwise.

[Driftwood Johnson]

most smokless loads have a lot slower pressure curve than BP unless its trailboss. Thats is pretty much a nanny myth when you look at factual lab tests vs myths. pulling a car on a rope vs gun loads is just silly vs lab tests. Plus the idea that most smokless powder has a higher pressure curve than smokeles is just ahh uneducated as any labortory tests will show otherwise.

Please post some comparative pressure curves, I would love to see them.

This is the only one I have. 18 grains of Smokeless vs 82 grains of FFg Black Powder. Both charges achieved 1200 fps with 1 1/8 ounces of shot. Pressure is in PSI, time is milliseconds. Notice not only is the pressure curve with the Smokeless load much higher in amplitude, but it is of shorter, sharper duration. That is what I was talking about when I said the the sharp curve of the Smokeless load could shock the old steel. Yes, unfortunately I do not know exactly what Smokeless powder it was, I assume a fairly fast shotgun powder. But this comparison of pressure curves illustrates what I was talking about.





As an aside, the rope comparison was only meant to be an illustration of the principal of what happens when force is applied slowly and steadily, as opposed to a sharp rapid application of force. Not any sort of verified lab test, just an illustration of principal.

[Hawg]

First off, the Pawn Stars 'expert' an idiot.

You got that right.