Sorry if I offended any owners of the .22-250, but barrel burnout is a reality and is caused by velocity, heat, and pressure. ANY cartridge that produces more of these factors is going to be more prone to burn out. Hunters usually won't be troubled by it, but shooters would. I was able to find a few informational items, like this statement from Guns and Ammo Magazine(Dec. 2004):
"Faster cartridges are going to wear out barrels more quickly than slower cartridges. There is no real threshold that I'm aware of, but the very fast .22s like the .22-250, .220 Swift and .223 WSSM are going to wear out barrels much faster than milder .22s like the .222 and .223."-Craig Boddington
If I'm wrong in this opinion, I have a lot of reputable company.
Obviously if you load a cartridge down below the levels for which it was designed, you'll prolong the rifle barrel's life. Then again you'll never attain the level of performance for which it was developed either. In which case you would probably be better off with a cartridge that was developed and designed for the performance level to which your loading. This is like buying a .44 mag. and then loading it down to .38 Spec. levels, it just don't make any sense.
Don.