Dante wrote:
I need to run some new wiring up from the basement into the wall. Is this
concrete that the wiring is currently run through? It's not very dense but
very hard. Instead of drilling another hole I was thinking I could cut the
armored cable from the top and then just rip it out from the bottom. Could I
then just run the romex through that hole.

Looks like concrete, but don't understand the "not dense" part...

If you don't need the existing cable, if it will come out, sure.

If you used a proper abrasion collar at the ends you could probably use
the existing armored as a sleeve/conduit for the new for such a short
distance.

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