To much fun

[dynomike]

I shot my Mountain Howitizer yesterday and that was just to much fun. I could'nt get my camera going till we were through. But i did take a picture of the target it was an 18" bullseye only 25yds. and the ball was .200 under. I shot it with 2oz. of cannon grade and a 2.5lb lead ball, and no sights. We are going to pull the barrel next Sunday and bore the barrel since we found it was egg shaped. After a little tweeking i think we can get it laid in.

[cannonmn]

bore the barrel since we found it was egg shaped.

Did you build it or buy it?  If you bought it, what supplier supplies a barrel with an egg-shaped bore?  I have to guess it isn't steel-tubing-lined since if it was, the bore would be round.

Looking fwd to hearing more about this interesting cannon.  The group isn't bad at all for an egg bore.

Thanks!

p.s.


You know what they call the residue you get in an egg-shaped bore after firing don't you?






It's called fowling.

[dan610324]

 

[dynomike]

It's a Hern barrel. I bought it used, the man i bought it from shot a lot of blanks through it. We figured since the liner was in there when it was cast might have caused it. I am going to contact Hern and see if they know anything about it.It has a 1/4" steel liner.

Let me change that. The liner is egg shaped on the inside.

[RocklockI]

fouled ! ...

[GGaskill]

I have a piece of 1" wall seamless tubing waiting to be completed as a cannon barrel and I can tell you that the inside is NOT anywhere near as circular as one would expect from drilling or boring (within a few thousandths of true round.)  I don't know how out of round your bore is but it does not surprise me.

[dan610324]

if hern cast their barrels horizontal, that mean the mold is filled from the bottom ( side in this position ) and up
so they first heat all the liner in its full lenght at just a tiny spot first and more and more when the mold is filled
maybe heating the full length from just the bottom and slow fill it will make it less round
I dont know , just a thought

I believe it would be much better to cast it vertical and fill from the bottom of the mold ( from the breach of the barrel )

when the mold is half full when poured in a horizontal position you have half the liner hot and the top half still cold
maybe that also could bend the liner slightly that you also get a curved bore, as half the liner is hot and the other half cold

just thoughts, any idea guys ??

[GGaskill]

Casting with a hollow core has a number of interesting problems associated with it.  Old barrels were made that way until it became possible in the middle 1700's to drill them from solid.  Then in the 1850's or '60's, T. J. Rodman developed the wet core process for cast iron guns that was adopted by most people still casting barrels.  But the wet core was drilled out to form the actual bore, I think.

[dynomike]

Joel Brown w/Hern said it did'nt get out of there like that. What might have happend the one that had it before me could have caused this by shooting under sized balls in it. I do'nt know. I also asked him why are the trunions tapperd. He said the one before me probaly did it to fit a carrige. I my be wrong but if the trunions had been turned i think i could tell.

[RocklockI]

i am sure the current hern barrels are excellent . 

mt have what i am sure is a hern 1840 6lber that is old . i dont think it has the same bore as now . but it is identical to the one in the website and t told me that it weighed 250 lbs .....

it is kinda rough ...as far as casting ...the rings behinfd the muzzle swell ...astrigills , fillegries ...whatever .

not smooth with parting lines lenght wise down that barrel . to the point that it would be hard to turn and true up the tube .

it is under about 20 years of dust . so i havnt seen the entire thing . and the castable is nowhere near round ,ish or nice .

i am sure that herns are fine now , besides it MIGHT not be a herns , and i could be wrong . but i know the folks on this board would not accept such a thing ...

[dan610324]

any rough iron casting can get a nice and smooth surface with a lot of work
but how smooth was the originals ??
Ive seen cast iron originals that had a very rough surface even if they are guaranteed to never have been rusty, so the original quality varied a lot. but I also seen very fine samples
but much of the difference in surface quality can also be because of different age
"old" iron cannons (1700) are often a bit rough, but semi modern cannons (mid 1800) are often smooth as an babys a§§
but most of the semi modern pieces (or almost all) have been machined at the outside also

the bronze pieces from early 1600 are absolutely not machined on the outside, and they are often extremely smooth , ok there are some rough castings there also