If it won't shoot, I'm going to blame it on the rotten, pitted, eroded bore.
Here's a look at what I will have to deal with:
I don't know whether a bullet will even slide down that dark and rough bore!
Oh no. And the rifling is all twisted too. What a disaster.
As an aside, my barrel looked not quite that good, but was really nice. It took, however 45 shots through it with varying grits of grinding compound on the noses of some bore riding nose bullets of .4575". I had to re-chamber it to .450 Alaskan in order to be able to use the larger bullets.
A friend of mine just HAD to have it for bear, so I no longer have it. It shot well with 400 and 505gr. bullets.
20" twist was normal, BTW.