The amount of leading you'll see with bare, lubed lead bullets is completely dependant on the gun and the bullet. What doesn't foul up one gun may foul up 100 others and vise-versa. Back in the 80's, being young and broke, we not only shot the cheapest guns we could find but also the cheapest ammo and yes we had mucho leading problems. Due to that I switched exclusively to copper washed/plated when shooting bulk ammo and I've never had a problem since. Only use bare, lubed lead when shooting better ammo for punching paper.
Now some have argued with me that the copper wash is too thin to have any bearing on leading what so ever. I can't argue that's it's thin but in almost 30 years of shooting I have had zero leading issues with any copper washed/plated ammo I've used. Maybe it's the extra lube qualities of the copper, maybe the copper isolates the lead, maybe ammo quality but the fact remains is there is a difference.