Jacketed versus bare lead, which is easier on the bore? .22 and .17?

[His lordship.]

It has been my impression that regular lead bullets are easier on the bore for longevity versus the copper jacketed ones.  However, I have read that the .17 HMR cartridge, all of which are jacket bullets, are not hard on the barrel, the heat of them is so low that shooters have been getting lots of mileage on their guns.  The opposite has been true with stuff like the 22-250 center-fire cartridge.

I also shoot center-fire rifles and it is known that heat erodes the chamber area of the barrel, so I keep my rate of fire down to 5-10 shots, allow to cool, repeat.  With the .17 crowd saying they can shoot alot, am I really in danger of shortening the life of my .22 rim-fires with copper jacketed ammo?

Thanks.

[Keith L]

I have never heard of anyone shooting out a rimfire.  I suppose that it is possible, but the heat and wear just aren't there like with the hyper velocity centerfire rounds.  We should be so lucky as to wear out our guns...

[semperfi1970]

Never seen a worn out 22.lr barrel. Have seen barrels that would lead up but that is in part to poor rifling and a bad overall bore. Older balard rifled .22lr barrels may lead up as the lands are tall and the grooves deep with chatter tool marks. A modern micro rifled barrel should never lead regardless of what .22lr ammo you shoot. If accuracy fades its more than likley the chamber is fouled and needs to be cleaned up a bit. Q-tips and solvent will do the trick.
Never seen a need for .22lr copper wash bullets, I think it is a good marketing tool like nickle plated brass.