Thoughts on testing barrels to destruction.

[Victor3]

 With armorer77's interesting test....

http://www.gboreloaded.com/forums/index.php/topic,182123.0.html

...I think it might be good to discuss some related points in a separate thread.

 This test proved exactly one thing to me; that this one particular barrel survived a massive overload without bursting.

 However, what may have happend if...

 1. The material had an undetected flaw (inclusion, void, etc)

 2. The barrel had an OD of 1/4" less

 3. There was a stress riser present in the internal form

 4. The barrel had a welded breech plug

 5. The barrel was held solidly so that it could not recoil

 6. The bore was 2x as long

 7. The steel was actually 12L14, but mis-marked as 1018 by the vendor

 8. There was .010" windage

 9. The 1st ball (under 3 lead balls) was a standard golf ball

 10. 1100 grains of powder was used

 11. Any combination of the above

 While informative (and not at all to detract from its significance), I'm concerned that armorer77's test could be viewed by some as 'proof' that it's safe to fire other cannons with similar excessive loads.

 I hope not...

[KABAR2]

While informative (and not at all to detract from its significance), I'm concerned that armorer77's test could be viewed by some as 'proof' that it's safe to fire other cannons with similar excessive loads.

 I hope not...

I think that anyone here knows this was a destructive test and that in no way should they stress their barrels to the extent that this one was taken to.

In view of the fact that safety is one of the first and foremost topics here I do not think anyone will view this as license to overload their cannon,  first off

none of us have a death wish or want to put others in danger,  I would think all of us respect the power of the propellant involved so the chance that someone

will think they can load it to the brim and load 4 pounds of lead on top of it  is doubtful.  There is always a chance that some Forrest Gump could read the test results

and think this would be a cool thing to try,  and even that would be a rare occurrence.

[Victor3]

While informative (and not at all to detract from its significance), I'm concerned that armorer77's test could be viewed by some as 'proof' that it's safe to fire other cannons with similar excessive loads.

 I hope not...

I think that anyone here knows this was a destructive test and that in no way should they stress their barrels to the extent that this one was taken to.

 Allan, I must note that "anyone here" may not include those new to cannons who don't enjoy the safety perspective that we have gained over the years on GBO.

 Respectfully,

 Victor

[armorer77]

I hope no one takes what I did as proof that we normally shoot "sissy loads" . One thing I learned was you don't have to stress a barrel to have fun . Maybe at another time I will try again with a longer barrel . Armorer77

[GGaskill]

I don't think a longer barrel would make any difference in the breech pressure achieved.  Black powder is not a progressive burning propellant (at least not in the form that is available) so it reaches maximum pressure almost immediately, not farther down the barrel.

[gulfcoastblackpowder]

There is one thing that can be assumed from this test - that another cannon, built from the same stock, using the same methods, in the same dimensions, fired with the same powder, rounds, and loading procedures, in the same mount, should have a similar result.  This is not important at all if the gun is unique, but armorer77 does manufacture and sell these, so it does give him and his customers some measure of comfort that their cannon is safe, especially at recommended loads, and that in a worst case scenario of the cannon ending up with a dimwit at some point down the road, they have minimal chance of causing harm to others with it.

[armorer77]

After reading and considering your concerns ,I am making one more shot . All my barrels are bored from solid bar stock so I can"t address that concern but I will try to add as many into the final shot as possible . Armorer77