Gunman;
First off I have never laid any claim to being an engineer, I am retired from working a number of years as a machinist, the majority of it as a modelmaker & have so stated. Previous to that I was a factory worker & farmboy. This is all I have ever claimed to be.
When you made the statement;
" When they are built the muzzel ends are brrought together to be parralel"
it was in no way stated they were parallel to any particular plane, vertical or horizontal. I have over the years worked with many things which were parallel to some given plane, but in this case the implication as written was they were parallel to one another.
I do accept your explanation. Perhaps I was a little hasty, but was simply responding to what I read, which I really believe you will have to agree that is what you actually said.
Another thing I have never professed to be is a Seer, I don't read minds, only the written or spoken word.
I have incidently heard the claim before that the bbls were pulled together for the last few inches in such a way the bores were parallel there. They were not proclaimed to be straight, which of course is where the impossibility came in. I have never seen a set of bbls put together this way either.