The formation of short Bragg gratings in SMF-28e non-hydrogen loaded pristine fibre using a cw Ar+ laser operating at 244 nm is reported. Mean refractive index changes >10-3 were obtained for a laser intensity of about 513 W/cm2 and a total dose of 5.9 MJ/cm2. Strong stress changes indicate a contribution of compaction to the refractive index change.