What is the view on using a Tornado brush to clean Chambers and bores on older shotguns? Damascus? Safe, not safe? Thoughts?

Great question.

This is just my opinion, but I use them on all my guns. My idea is this ....... that the way the strands in the tornado brush are looped, without any sharp ends to contact the bore, there will be no more likelihood of bore damage than with any
other style brush. I do not hesitate to use them on any of my vintage guns, and have never noticed any bore damage.

If there is evidence of bore damage from using them on vintage guns I would also be most appreciative to hear of it.

I use them in all my shotguns . They clean better than any brush I have tried no damage to Damascus. prove how good they do clean one bore with a bristle brush and the other with the Tornado brush. Look through the barrels at a light source. than run the tornado through the bristle cleaned bore. you will see a difference. They work dry with no cleaning fluid better than a bronze brush with cleaning fluid.

There's a reviewer on Amazon that says it scratched the bore of his 'golden era' shotgun, presumably because the stainless steel is harder than the old barrel steel. Not saying his experience is worth more than Stan's or GMCS, but it is a dissenting voice to the discussion.

I don't see how the Tornado brush could do the damage that Amazon reviewer claims unless it was repeatedly reversed in the bore and developed a sharp end that was no longer part of a loop like Stanton Hillis describes.
I use them and it is a YES, for me.

Tornado brushes are great for removing plastic fowling from chrome lined bores....

Common sense tells me I don't want to use a brush that is made from a material that is harder than the barrel you are cleaning.

There is nothing wrong with using a brass or bronze tornado brush. But there are other tornado brushes made of Stainless steel.
I would avoid using those on Damascus bbls. They could scratch the bores if they were to pick up any bit of steel from the bbl
or develop a sharp edge somewhere on the brush itself. They are ok for chrome lined or molybdenum bbls.

The Big 45 Frontier Metal Cleaner pad is far better than a tornado brush. Just cut off a piece of it, wrap around a bronze brush, and it’ll clean better than anything else. And it WILL NOT damage the bore! I spin my rod in an electric drill and run it back and forth. There will be NO lead or plastic remaining when finished. Only takes a minute or so in a drill. Pay special attention to the forcing cone and choke areas. And also it is great removing light rust from bluing without hurting blue.

https://www.big45metalcleaner.com/