Originally Posted by
Peter Laidler
I'd like to know more about the method used test the No4 barrel to destruction JSS. We tried to 'blow' one for a project but while we severely damaged several new ones, we couldn't get one to replicate a breech explosion that would blow the sealed breech. We formed the opinion that you wouldn't be able to get enough 'dynamite' in the case to blow it
I have seen thousands of No4's and 5's but never seen a breech explosion of the type you describe. On that basis, I'd stop fretting right now!