Can't have tried too hard with the rattle gun... the bolt head is not rounded yet
Put the nut back on the end until flush with the thread, then beat the snot out of the nut/bolt end with a bfh.
If that don't work, heat around the bolt (and the other end - bolt head) with an LPG torch. Won't melt the steel but will get it plenty hot. Cool, heat, cool then get the bfh out again.
Failing that, grind the thread and bolt head off (or make Dan do it with a file if powertools are banned

) then punch the remainder of the bolt out with a drift.
Cheers,
Harv
327 Chev EK wagon, original EK ute for Number 1 Daughter, an FB sedan meth monster project and a BB/MD grey motored FED.