clutch
1. Where did you think erosion started at, the muzzle or throat?
2. If you have a tapered barrel like the majority of us have, just how far do you think a barrel can be setback or shortened and re-chambered for your .308?
Throat erosion is governed by chamber pressure and powder burning rate and more barrels are damaged by improper cleaning methods than any other cause.
The target below was fired at 50 yards with a 68 year old .303 Enfield with cordite throat erosion and iron sights. Cordite powder has more nitroglycerin than many double base pistol powders have today and caused more throat erosion than any rifle powder we have today.
I just sold off many of my Enfield rifles so I could buy new rifles with tight chambers because I wanted my "brass" to last a long time.
(the last thing I'm worried about is bore erosion because its going to happen on any rifle above 43,000 cup)
If your worried about throat erosion buy a 30-30 or a cartridge with less than 43,000 cup chamber pressure. Your barrel erosion will be governed by how "HOT" your loads are. AND your loads will be governed by how accurate they are and accuracy trumps bore erosion.
Bottom line, pick your favorite cartridge and shoot it till you need a new barrel.
(its not the age, its the miles)
and how hard the mileage was
If your still worried about throat erosion after read above then join the Savage/Stevens barrel nut club and change your own barrels.
I wanted a .308 but settled for a .243 with more bore erosion than the .308 but thats what happens during a sale and they run out of .308, and I'm not crying about it.
243 Win Cartridge Guide
High-Velocity 6mm for Long-Range, Varminting, and Tactical Use
http://www.accurateshooter.com/cartridge-guides/243win/