FWIW:
Don't know about rugers but I did burn thru some rounds in a s&w 586 that I bought NIB back in 1987. That 586 got a diet of anything from target loads in 38spl cases to hot 170gr 357 loads. 99% of the bullets shot in it were lead/cast bullets. Used to buy cases of the ww820 pull down powder to burn in that 586 & a couple 44mags. A case of ww820 ='s 4 8# jugs/32# of powder. Burned a lot of ww452/trap 100 in the 38spl cases.
At the 100,000 round mark I had to send that 586 in to s&w. They re-did the timing cut the bbl back and re-cut the forcing cone.
At the 200,000 round mark I had to send that 586 in to s&w. They re-did the timing cut the bbl back and re-cut the forcing cone.
At the 275,000 round mark accuracy went south along with I was loosing 40+fps with loads that I shot for years. What the bbl looked like
View attachment 851805
It's hard to see in that picture the drive side of the lands are rounded out. The non-drive side of the lands is still fairly crisp. The holes in the cylinders were bad. they had a noticeable step starting to form in them.
View attachment 851806
I re-barreled that 586 & put another cylinder on it. Shot it for awhile and ended up selling it. Just never liked the feel/balance of a 4" bbl'd 586.