Miller Millermatic 255 MIG Welder with EZ-Latch Single Cylinder Running Gear 951766 can run .030 solid. You would need to change the liner tips and drive rolls.
Miller AccuLock S Series .030 MIG Contact Tip T-A030CH
Miller AccuLock MDX .030/.035 15 ft. MIG Gun Liner LM2A-15
Miller Drive Roll Kit - .030 V Groove 2 Roll 079594