is assigned to the assignee of the invention pellets 28 fig5 from the pellet source not shown flow through a flexible transport hose not shown to tube 1 and thence into the nozzle area where they are accelerated to sonic velocity and fractured to produce ragged edges for greater abrasive ability a support means comprising generally an entry tube 1 the entry guide 3 a spacer 5 a locating boss 15 and handles 17 and 20 support a nozzle 19 the entry tube is held in place by a spacer 5 which is located between an entry guide 3 and a locating boss 14 this assembly allows an operator to rotate the nozzle assembly about its longitudal axis within the limits of rotation of the stop 13 which comprises about 90 u00b0 either side of the vertical handle position the nozzle 19 slides into the guidesleeve 9 and is rotated to a locked position in a bayonette block 8 the antirotation latch 10 which is spring loaded by spring 16 locks the nozzle to prevent rotating and unlocking the latch release handle 15 unlocks the nozzle for removal the nozzle seal 11 is retained in the nozzle and provides sealing between the entry tube and the nozzle entrance against air leakage a pistol grip handle 20 supports a trigger.