Question about HEF shotgun receivers- Metalurgy?

[preventec47]

Here I have been thinking about having a small dovetail cut into the receiver
behind the barrel and in front of the hammer and someone asked if that
was hardened metal as in tool steel etc.    I dont know.  Could this metal
be cut with a file or hacksaw or bit on a mill ?      Has anyone ever
tried to drill a hole or in any way cut into the steel on a shotgun
receiver?    We hear a lot about the Shotgun receivers being
weaker than the Rifle receivers.... Is the difference heat treatment
or other tempering ?  If not that then exactly what is the
difference that makes the shotgun receivers weaker ?
Thanks
Scott

[quickdtoo]

SB1 frames are cast iron, SB2 shotgun frames are heat treated investment cast alloy steel, same as the SB2 rifle frame.

Tim

[preventec47]

Finny, I know my shotgun is the SB-1 but I always assumed it was marked
as such.  It is a Pardner and nowhere that I can find does it say SB-1

I checked one time and I think it is about 9 or 10 years old.

[quickdtoo]

Frames are never marked, only barrels on some models and it doesn't mean squat since they put SB2 marked 357mag rifle barrels on SB1 frames now. Frames differences are shown in the FAQs and Help sticky a good place spend some time reading to learn more, that's what it's there for. 

Tim