I have a stainless 308 barrel (somewhere) that I bought intending to have JES rebore/rechamber to 338 Fed, but Mr. O told me that he had done a couple of 99s in 338 Fed and the owners were reporting high pressure signs with factory ammo, so he recommended against it. I have always thought that Mr. O turning down work spoke highly of him, as only honest people will turn away work/$$.
