4seventy, There was a guy over on AR that had a Chapuis double rifle, that the ribs, and barrels seperated on. He sent it back to the factory, as the rifle was new. The Factory fixed the rifle, and sent it back to him! Two weeks later the barrels seperated again, so he sent the rifle back to the factory again. They called him on the phone, and questioned him as to what he had been shooting in the rifle. When they found out had shot Barnes Mono-lithic solids in the rifle they hit the cealing. They told him they would fix the rifle, but if he shot mono-metel bullets in it again, he was on his own.
According to the owner of this rifle,tey told him the bullets were too hard, and the sudden movement of the bullet in the thin barrels, the expansion of the barrel as the hard bullet traveling through the barrel over stressed the solder holding the ribs, and barrels together, causeing them to let go!

Also, 400NitroExpress, who posts here knows of this instance, and has personally examined one rifle with the over stressed rifleing! When looking down the outside of the barrels, along their length you can see the slightly raised steel over the rifleing, on the outside of the barrels. It is very slight rise, but can also can be felt with the fingers, when runing them down the length of the barrels. This last paragraph is what I was told by Mark, I didn't personally see it. And the thing with the Chapuis rifle was what was stated by the owner, but I can't remember if he posted a letter from Cahpuis, or not, since it has been three or four yrs ago!

I do not shoot most Monolithic solids in my double rifle regardless of age, except for the North fork CPS, and FPS,, and GS custom, with pressure rings, that do not allow the rifleing to engrave the solid body of the bullet, and the bullets are made of softer copper, not hard Bronze, like the Barnes. These bullets are so easy to push down the barrel thay can be pushed down the bore with a wooden dale rod, by hand, and the bullet will give higher velocity with the same load used with coventual bullets. ONLY the pressure rings are engravedby the rifleing, and rings are grouve dia, to seal the pressure behind the bullets.