I assume alum since a magnet wont stick,so why do they say made from extrusion which is the process of forming soft materal so i read.

They are indeed aluminum extrusions. The one I have and the others I've seen have all been very well made.

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Quoted: Some of the earlier ones (ar10) were made from bar stock but the latest models are made from an aluminum extrusion. Extruding is a way of forming aluminum and other metals into complex shapes. sometimes it is done to reduce machining time and cost but it also allows items to be made that might otherwise be extremely difficult if not impossible to machine. en.wikipedia.org/wiki/Extrusion

You are correct sir!  If I can extrude to get a specific shape and cut down my milling time its stupid to do it any other way and a waste of time and materials provided it meets the specs.
Its a fact!  Unless you just enjoy paying out of this world prices.

Quoted: Quoted: Some of the earlier ones (ar10) were made from bar stock but the latest models are made from an aluminum extrusion. Extruding is a way of forming aluminum and other metals into complex shapes. sometimes it is done to reduce machining time and cost but it also allows items to be made that might otherwise be extremely difficult if not impossible to machine. en.wikipedia.org/wiki/Extrusion You are correct sir!  If I can extrude to get a specific shape and cut down my milling time its stupid to do it any other way and a waste of time and materials provided it meets the specs. Its a fact!  Unless you just enjoy paying out of this world prices.

Nothing wrong with extrusions. They will do the job and are one reason rails are affordable (along with thousands of other items). Some of the shapes they can make are nothing short of amazing and would be almost impossible to make using conventional cutting machines. When I got out of machinist school I interviewed at a shop that made dies for extrusions and some of the samples are quite interesting. I didn’t take that job as they just wanted a lathe monkey to turn parts for the next 20 years.