"Thin barrel" question re: round ball

[Dphar1950]

And almost all the blowups concern percussion ignition. Though there was a photo of a re-enactor with a left hand missing on another site a few years ago that somehow did not make it into the archives, when his fowler burst at the too deep wedding bands (its a stress riser)

 

[FlinterNick]

Balderdash. I short-started my Kibler .45 SMR with a GM barrel and nary a problem, barrel unfazed, missed the target though. I've also failed to get the ball fully rammed a few times (learning curve with patch lubes, not swabbing between shots, and the fouling ring creeping up on me) and no problems at all, thank goodness. 70 grains of 3F. Maybe what they say about God watching over the ignorant and fools is true, or maybe it's good metallurgy and the laws of thermodynamics? Don't tell me it was because it's a flintlock.

A short start the muzzle patched ? I doubt that very much, and i woudln’t do it twice if i got lucky the first time.

 

[Brokennock]

What were you doing at the time? I was writing for the Buckskin report and there were a frightening number of blow ups. But since this was before, I suspect, quite a few here were even born I don’t expect them to understand. But when the barrels are made of materials that the STEEL makers specifically don’t recommend, things can happen. A number of us suspected that they changed barrel steels after a number of lawsuits. They said that they had put in an xray process. Something they would not need if they used the proper grade and alloy. But they could not admit that the steel they used initially was not suitable for any internal pressure application. This was ALL discussed in detail by a metallurgist who specialized in failure analysis. Who BTW seldom posts on any of the ML site since he gets manure from “experts”. The fact is that a GB quality steel with a 100000 psi tensile will not fail even with a short started ball. It will likely bulge. Before they stopped making ML barrels (they had some failures) a major US barrel maker was using cold drawn octagonal bars. Toward the end the barrels started to arrive with scale on them indicating they were normalised I.E. annealed to reduce the brittleness. Brittle and barrel steels is a bad thing. No all blow ups cause injury. One 45 cal I saw about 1969 split up the top flat from the face of the breech to the rear sight. The other factor was the use of Max-balls which greatly increased the pressure and shock loading. Did you ever wonder why the Union made Rifle Muskets of the Civil War all used skelp welded iron barrels and not steel? You might ask why. These were proved with 200 gr of Musket powder and a 500 gr Minie bullet seated 2” off the powder. Finally what I have posted here is fact not guess work. Its based on documentation that appeared in print from the people with issues, from steel makers, from metallurgists. You might ask about the Remingtom 870 blowups that resulted in Remington going just a little too cheap on shotgun barrel steel. This stuff had a tensile several times that of the pressure generated by shotgun shells. Yet there were failures with trap loads. People ask questions I give answers. The interesting thing is that a cheap leaded screw stock barrel may stand an immense overload and the next one fail with a service load or 10 years later with a service load or never. I simply would like to see a hot rolled Gun Barrel quality steel used. Not a steel that intentionally made brittle and loaded with inclusion causing “lubricants”. Meaning sulphur and lead for two. To make them free machining. Don’t like this don’t read my posts on subject. If you like I could post a photo of the letter sent to and published by John Baird from the steel maker LaSalle. But I suppose they don’t know what they are talking about either.

All those words, and still, no real numbers to support, "really took off."
You make it sound like barrels were blowing on a regular basis. I seriously doubt that to be the case.
Let's see hard numbers. How many barrels blew up in 1970, 1980,,,,, pick a couple years? Let's see that "take off," in hard numbers. How many barrels blow up, or were blowing up per thousand?

 

[FlinterNick]

All those words, and still, no real numbers to support, "really took off."
You make it sound like barrels were blowing on a regular basis. I seriously doubt that to be the case.
Let's see hard numbers. How many barrels blew up in 1970, 1980,,,,, pick a couple years? Let's see that "take off," in hard numbers. How many barrels blow up, or were blowing up per thousand?

All this argument does really is suggest that only high density heat treated alloy steels should be used for black powder barrels, which is only necessary if the barrel is very thin and light.

while it may hold relevance for some types of black powder gun barrels… for most it does not.

For example a long land brown bess barrel with a 1.5” breech is pretty thick for the first 20”.

the most important parting is how well it is breeched, most modern breeches are finder threaded but have more threads per inch, making it a tighter seal when it interfaces with the bore.

This barrel’s nominal cost to make is around $225-275 to sell in the market is around $400.00-450.00 in 12l14 OR 86L20.

Making that barrel is say 4130 or 4140 steel is fine, but will raise the cost from 275 to 375 and price it even higher on the market, and the heavier alloy steel is overkill for that type of barrel.

I was saw a test by Don Getz he loaded a 12L14 barrel three times the standard loadl, nothing happened, no crinks, bumps or swells or cracks.

Short started at the bore 8” with 100 grains …. It exploded.

He did the same test with a 4130 barrel, it exploded.

 

[Loyalist Dave]

So nobody answered the question of why some folks say don't shoot a round ball in a "thin" barrel....
Some answers were that they actually do such shooting....
Nobody provided a technical spec for what measurement makes a barrel "thin", compared to other barrels...,
The responses morphed into a discussion of steels used in barrels, BUT no information that the thin barrels the OP has encountered were made of that steel...

So the answer is, nobody knows... at least so far.... four pages is enough then.

LD