Are billet receivers advisable for precision long range 6.5 Grendel build?

[Frontier Gear]

Frontier Gear, could an extruded aluminum tube be made thin and strong enough for a magazine body?

Probably, but I guess I don't see the point in that. Extrusions are usually done to make manufacturing easier, such as with hand guards. It would be a pain to machine out that huge hole through the middle of the hand guard and leave such a thin wall. Extruding the basic hand guard shape and then machining in the rails, Mlok or Keymod cuts (along with any decorations) and machining it's attachment point is much easier. Also, extruding is expensive and requires special machinery, not to mention the cost of heating the metal to it's melting point. Sheet metal forming is easy and can be done with fairly common tools.

Magazines are formed from sheet. Sheet goes through the same process as plate. It is just rolled down to a much thinner final product, but it starts out just as thick. Sheet is also stretched, but it is not ultrasonic inspected (not much point to that at this thickness). So a magazine formed out of a sheet should be much stronger than one that was extruded. The variables being the construction methods and quality of the workmanship (welds, etc...). Also, anytime that you stamp aluminum sheet (as many magazines are), you are stretching it and therefor making it stronger. This is one reason why aluminum makes such good boats. If you hit a rock, the aluminum actually gets stronger as it starts to deform. That is up until it's point of failure.