Here is something intresting:
In fact there were two six barreled versions, this one and the A-1a/U1 (with three different cannon types 2 Mk103, 2Mk108 2MG151/20).
112355 Me 262 A-1a/U5. This experimental weapons prototype with six 30 mm MK 108 cannon was flight tested in March 1945. It was then transferred to JV 44, and flown by Major Heinz Bär to München-Riem on 23 April from Lechfeld. It was flown in combat by Bär from München-Riem, from where he apparently shot down two P-47’s on 27 April, and one P-47 at Bad Abling on 29 April. This is the only known prototype.