blackball229

Wasn't really comparing the two, just that all barrels have a life expectancy. Even at lower pressures there is a a shock factor every time the gun fires creating fatigue.If I fire it 20-50 times a day for the next fifteen years, your saying that barrel will be in perfect shape? You say liability is for "weaselly lawyers"? If my wife an son are shooting on the crew or anyone else for that matter,your damn right I would want to know how far anyone has thought this through. As a fabricator and designer for one of the largest and most famous themeparks in the US, this is what I do professionally.

The major difference between a period gun and a modern military field piece is the level of compression and barrel design... the metal fatigue that occurs in modern weapons is caused mostly due to the repeated intense compression inflicted on the metal of the barrel with close fitting diameter of the modern rounds used and the amount of propellant used to fire the projectile the distances required in modern warfare. Liability is for weaselly lawyers

I still think "one generation to the next" might be a bit too optomistic and could be a liability in the long run. Wow these barrels must be better than what our military uses because they have a finite number of cycles.

All of the guns the Viceroy builds are built to last from one generation to the next. The problems you mentioned are not prevelant in many of the smaller guns since they are cast the same as some of the newer originals solid then bored out. As for the difference of metals if a touch hole is threaded in it would be replaceable and would isolate the the charge completly from the various metals. Of course the large guns "could" be cast as a solid bronze and then bored out but $$$$

I'm not sure any liner will last from one generation to the next. As a fabricator for one of the premier themeparks, I've built many projects where we were forced to reevaluate our thought on absolutes, when it comes to safety.Absolutes only last untill that one occurrance happens that our egos wouldn't let us look at. Time will only tell how long something will last. I've done restoration on various historic projects where the original builder or designer had great innovation but stopped short on thinking the technology all the way through, or stopping short and saying this will suffice. When other lives are at stake over thinking is really the best policy.The shock from repeated firings over time will effect most metals unless the sidewalls are extremely thick. My concern is that we have liners 1/4 inch thick press fit into castings with a seal issue around the touchhole. The repeated firings and cleanings would be forcing gasses, carbon aluminum oxides into the gap. However small it is, when the guns are washed, moisture will sit there and begin to oxidize the sidewalls building pressure between the the two. Add the shock of repeated firings, there are some unknown factors created. There is a point where it could become dangerous.

The particular guns that are mentioned being hollow cast in bronze with the steel liners are the ones I will be refering to.

The liner is proofed prior to the gun being built so the porosity or weakness of the casting around the bore becomes irrelevant. The touch hole is a concern since it would be drilled thru bronze aluminum and steel which is a poor combination to say the least. As an alternative it is possible to tap the steel inside and have a threaded touch hole and have a piece threaded into the sleve that would be able to be replaced the same as a musket or pistol. As for longevity the guns that we build are made to last from one generation to the next and on down the line.

Ahh, wonderful to find some true knowledge on this subject

My group is firing sleeved barrels, several shows per weekend, and then doing the usual cleaning at the end of the weekend, pouring water down the barrels, brushing and using bore butter. As a fabricator and a son of a master machinest, my questions are these.

1 Since the barrels are pressure fit into the casting and the touchhole drilled afterward, there is no true seal between sleeve and casting. there will be a buildup of powder residue and rust over time. Having rebuilt historic machinery and architecture pieces for years, I've seen how this type of buildup can cause expansion pressure. How safe is this over time?

2 How many actual firings would be considered safe before retiring barrels?

3 There was also a mention of honecombing of barrels over time. Is this just relative to cast iron? what about the sleeves, how do they react over time to firing?

4 Shouldn't our master gunner be keeping a detailed log of firings?

5 We use aluminum foil for our charges, you mentioned an incident involving aluminum foil. What are the pros and cons of foil charges?

I'm relatively new to the group, and the people in charge have been lording their methods and knowledge as absolute. Me, having been a machinests son,a fabricator and a shooter since I was 12 have some serious doubts about the safety of the group.

What are your thoughts, and what else should I been considering?

The problem with an unknown core casting, gun cast with the liner in place , is many fold. The liner and the breech plug in the liner should be of a construction to fire the charge without the iron around it. In such a casting the molten material can cool off too quickly on contact with the steel liner ond become weak or porous .The vent when drilled may not be true but have spark hiding cavities. There have been attempts to solve these problems, but the best way to build a sleeved gun is to cast it solid,better trunnions too, and bore the tube then press the properly breeched liner into the tube. If you don't know the maker you don't know the construction of the gun. Then an X-ray such as used for aircraft castings is about the only positive way to be sure. Proof firing an unknown gun only tells you it's safe through the last shot. I too know two one armed gunners, one involving the use of aluminum foil, there are no small cannon accidents. Think, what would be the acceptable percentage of failures? One of the true examples of zero tolerance for accidents.