Is it safe to use an Air Chisel on a brake drum?

[1968SWBBigBlock]

Ok its all apart
1 - one of the pin and cup assemblies fell out which prevents the adjuster from moving the back shoe - hence it is held in the wrong location, in traction, by the springs
I cut a window into the drum with my angle grinder- used my jigsaw to cut the adjuster - as soon as it was out of the way the drum came off
No hammer was going to take this off without more damage occuring unless the drum broke
Regarding cutting the nails - I considered this but was afraid I might damage the wheel cylinder going that route. In the end I think it would have been just fine.
One of these days I going to buy myself a fire wrench just for occasions like this.
I pulled the other wheel tire and drum of in less than one minute - just the way it should work.