Finally, someone answered the question of whether bitmetal jacketed ammo is bad
This morning I woke up, sat up in bed, and read the most recent issue of Front Sight, the USPSA magazine.
Someone finally did an intelligent article on Russian bimetal ammo that is so popular nowadays. To make a long story short, using such ammo may shorten the life of your barrel. This is because the copper jacketing covering the steel jacketed bullet is extremely thin and tends to get entirely rubbed off in places while still in your barrel, so your barrel ends up being exposed to steel from the bullet.
The author used some university laboratory equipment to ascertain the composition of various Russian manufactured bullets, and also to determine how much material had been removed from bullets after they were fired from various firerams into a medium from which they could be recovered intact. According to the author you can see the thinness of the copper jacket for yourself if you take a piece of sandpaper to some of these bullets.
Sellier and Bellot, which is what I shoot through my .45, is okay, though, because the way that they economize is by using 30% brass and 70% copper in their jacketing, as opposed to 100% copper. So if you want to shoot cheap Eastern European ammo without running steel down your barrel, that could be the way to go.
I encourage everyone to read the article. Interesting stuff.