[tkbigbore]

I have a shotgun made from 4140 steel(barrel+bolt) and 7012 aluminum (receiver etc)
How strong or quality are these metals?

 

[miestro_jerry]

4140 is really the standard steel for guns. I believe your 7012 is actually 7012–T7352 alloy for guns. It is a good alloy, I machine a few things from it now and then. It is a aluminum, iron and silicon alloy, not sure of the percentages any more.

Jerry

 

[tkbigbore]

there barrel has a chrome like finish on the inside which i thought was odd since my other shotgun doesnt have a chrome barrel .for a cheap gun anyhoo

 

[bldsmith]

Any Steel and most metals can be polished to a mirror like finish. It does not have to be chromed to look shiny. 4140 is a chromium steel but it is for strength and not finish.